Abelisaurus Bonaparte & Novas 1985 "Abel's lizard"
ah-BEL-i-SAWR-us (Abel + Gr. sauros "lizard") (m) named to honor Roberto Abel, director of the Museo de Cipolletti, Cipolletti, Argentina, who found the specimen. Theropoda Abelisauridae L. Cret. SA
Abrictosaurus Hopson 1975 "awake lizard"
a-BRIK-to-SAWR-us (Gr. abriktos "awake" + Gr. sauros "lizard")* (m) The name expresses J. A. Hopson's "disagreement with [R. A.] Thulborn's suggestion that heterodontosaurids underwent aestivation (or hibernation) during the yearly dry season," based on the supposed replacement pattern of their teeth. Abrictosaurus was active year-round in Hopson's view. Ornithopoda Heterodontosauridae E. Jur. SAfr.
Abrosaurus Ouyang 1989 "delicate (skull) lizard" [xiulong]*
AB-ro-SAWR-us (for Gr. habros "delicate, light" + Gr. sauros "lizard") (m) referring to the very light construction of the skull, characterized by extremely large openings (elliptical-shaped external nares, triangular-shaped antorbital fenestrae, orbits, lateral temporal fenestrae) separated by very narrow bone structures. Abrosaurus is a relatively modest-sized camarasaurid-type sauropod (probably about 7-9 m (25-30 ft) long); with a relatively short neck consisting of 13 cervical vertebrae with centra about 1.3 times the length of the dorsal centra. Neural spines simple and relatively low on cervicals, but slightly forked on anterior and posterior dorsals; dorsal centra platycoelous or weakly amphicoelous. Skull is about 46 cm long; the mandible is long and thin; teeth are comparatively small and spatulate in shape. Forelimbs 3/4 the length of hindlimbs. Known from a nearly complete skull (Holotype: ZDM 5038 (Zigong Dinosaur Museum)), parts of a skeleton, and a second skull, found in the Middle Jurassic Lower Shaximiao Formation, Dashanpu, Zigong County, Sichuan Province, southern China.
Type Species: Abrosaurus dongpoensis [doong-paw-EN-sis] Ouyang 1989: "for Dongpo": named for Su Dongpo, pen name of Su Shi (1036-1101 AD), famous Song Dynasty writer and poet born in Sichuan Province where the fossils were found. NOTE: a description of Abrosaurus published in 1996 (Zhang & Chen 1996) gave the type species as Abrosaurus gigantorhinus ["giant snout"], based on an unpublished dissertation by Ouyang in 1986; the Ouyang's official description of Abrosaurus published in 1989 in the Zigong Dinosaur Museum Newsletter (1989 (2)) made the type species A. dongpoensis. Sauropoda ?Camarasauridae Middle Jurassic China [added 8/2000]
Acanthopholis Huxley 1867 "spine-scutes"
a-kan-THOF-o-lis (Gr. akantha "spine, thorn" + Gr. pholis "scute") (f) referring to the "large scutes and spines entering into the dermal armor of....a large reptile allied to Scelidosaurus, Hylaeosaurus and Polacanthus." Ankylosauria Nodosauridae E. Cret. Eur.
Achelousaurus Sampson 1995 "Achelous lizard"
ak-e-LOH-uh-SAWR-us (Achelous (Gr. Akheloos), a mythical river god + Gr. sauros "lizard") (m) named for Achelous, a river god in Greek and Roman mythology who could change shape at will. He transformed himself into a bull to fight Hercules, who defeated Achelous by tearing off one of his horns. The name alludes to the way a large hornless dinosaur evolved from earlier horned ancestors, and the way the animal appears to be a kind of shape changer, since it combines the frill of Einiosaurus with the nasal bosses of Pachyrhinosaurus, two closely related genera. Ceratopsia Ceratopsidae Centrosaurinae L. Cret. NA.
Achillobator Perle, Norell & Clark 1999 "Achilles (tendon) hero"
a-KIL-o-BAH-tor (Gr. Akhilles (mythical Greek hero whose only vulnerable spot was his heel; his name is associated with the tendon that runs along the heel bone) + Mongolian bator "hero") (m) alluding to the powerful Achilles tendon [tendo calcaneus] that must have existed along the "heel" on the second phalanx of dromaeosaurs, for attachment of the large flexor muscle that permitted slashing blows from the huge claw on the second toe: "The penultimate phalange of the second digit [in Achillobator] is massive with a hypertrophied postero-ventral heel, which probably served as the insertion area of the flexor of the digit tendon." Achillobator is known from a fragmentary partial associated skeleton (Holotype: FR.MNUFR-15 (Mongolian National University, Ulaan Baatar)), consisting of a left maxilla, left femur and tibia, left metatarsals III and IV, right ilium, pubis, and ischium, isolated phalanges from the feet and hands, tooth fragments, isolated caudal vertebrae, and fragments of ribs; collected in 1989 at Burkhant, southwest of the village of Dzun Bayan, near Khongli Tsav, Southeast Gobi Desert, Mongolia, in the Late Cretaceous (Late Santonian/Early Campanian) Bayan Shireh Formation. The fragmentary maxilla (upper jaw) bone indicates Achillobator had a large skull "similar in proportion to carnosaurs." The pubis is long and robust, with a foot-like distal expansion similar to "carnosaurs"; the pubis is also oriented much more forward than in typical dromaeosaurs, which have an opisthopubic, or backward-pointing pubic bone. The surprising combination of a primitive "carnosaur"-like pelvis with a raptor-like toe-claw sets Achillobator apart from other known dromaeosaurs. The formal description of Achillobator was published by the National Museum of Mongolia based on an extremely preliminary manuscript without the knowledge of the junior authors (Mark Norell and James Clark). This incomplete scholarly process poses problems for some details and conclusions found in the original paper. Burnham, Derstler, Currie, Bakker, Zhou and Ostrom (2000), in their description of Bambiraptor, suggest that the taxon may be based on "upon of mixture of bones from two or more actual species," with only the pedal unguals being identifiable as dromaeosaurid material, while "the ilium, ischium, maxilla, and caudal vertebrae share no unique features with the Dromaeosauridae."
Type Species: Achillobator giganticus [ji-GAN-ti-kuhs] Perle, Norell & Clark 1999 "gigantic," to indicate its very large size for a dromaeosaurid--the proportions of its femur (50.5 cm long compared to around 30 cm in Deinonychus) and other bones suggest it was likely at least a third to twice as large as Deinonychus, perhaps up to 6 m (20 ft.) long with a 13 cm long slashing claw. The original description suggests Achillobator was "three times as large as Deinonychus," but this estimate appears to be an error.
Theropoda Maniraptora Dromaeosauridae Late Cretaceous (Santonian/Campanian) Mongolia [added 5/2000]
Acrocanthosaurus Stovall & Langston 1950 "high-spined lizard"
ak-ro-KAN-tho-SAWR-us (Gr. akros "high" + Gr. akantha "spine, thorn" + Gr. sauros "lizard") (m) named for the raised ridge of neural spines along its back. Theropoda Carnosauria Allosauridae E. Cret. NA.
Adasaurus Barsbold 1983 "Ada's lizard"
AH-dah-SAWR-us (Ada + Gr. sauros "lizard") (m) named for Ada, an evil spirit in Mongolian mythology. Theropoda Dromaeosauridae E. Cret. CAs.
Aegyptosaurus Stromer 1932 "Egyptian lizard"
ee-JIP-to-SAWR-us (Gr. Aigyptos "Egypt" + Gr. sauros "lizard") (m) referring to Marsa Matruh, Egypt, where the fossil was found. Sauropoda Titanosauridae E. Cret. NAf.
Aeolosaurus Powell 1988 "Aeolus's lizard"
EE-o-lo-SAWR-us (Lat. Aeolus, god of the winds in Greek and Roman mythology + Gr. sauros "lizard") (m) alluding to the windy Patagonian region of southern Argentina where the fossil was found. Sauropoda Titanosauridae L. Cret. SA.
Aepisaurus Gervais 1852 "high lizard"
EE-pi-SAWR-us (for Gr. aipys "high, lofty" + Gr. sauros "lizard") (m) named to indicate a "great saurian... whose humerus, with a size approaching that of an elephant, notably recalls, in its shape, that of a Varanus." Sauropoda i.s. E. Cret. Eur. [nomen dubium]
Aetonyx Broom 1911 "eagle claw"
ay-EE-to-niks (Gr. aetos "eagle" + Gr. onyx "claw") (m) probably alluding to a large toe claw on the second digit with a "combing or scraping edge such as is seen in many birds" and which Broom thought might be used in grooming the animal's supposedly long scales. [= Massospondylus]
Afrovenator Sereno, Wilson, Larsson, Dutheil & Sues 1994 "African hunter"
AF-ro-vee-NAY-tor (Lat. Afr- (Afer), inhabitant of Africa + Lat. venator "hunter") (m) named to indicate a large, allosaur-like carnivore found near In Abaka, Niger, in the southern Sahara region of Africa, thus A. abakensis ah-bah-KEN-sis "hunter from In Abaka, Africa." Theropoda Tetanurae Torvosauroidea E. Cret. NAfr.
Agathaumas Cope 1872 "great wonder"
ag-a-THAW-mas (Gr. agan "much, very" + Gr. thauma "wonder, prodigy, monster" + -as [Gr. masculine noun suffix]) (m) alluding to its great size. Cope says: "the forests [of the Cretaceous]...were inhabited by these huge monsters." The type specimen lacked a skull, and does not appear to be diagnostic, although it seems probable that it is a skeleton of Triceratops. Cope originally classified the form as a hadrosaur and did not recognize the genus as a horned dinosaur until Marsh described Triceratops in 1889. Cope later proposed that both Triceratops and Monoclonius were junior synonyms of Agathaumas. Charles R. Knight's fanciful 1897 painting of Agathaumas, done under Cope's guidance, combined Marsh's skeletal reconstruction of Triceratops prorsus with a long straight nasal horn that Cope previously had identified as Monoclonius sphenocerus (the spectacular horn may come from a Styracosaurus). Knight also depicted the supposed "dermal armor" that Marsh mistakenly attributed to Triceratops, material now identified as spikes from the skull of the pachycephalosaur Stygimoloch and scutes from an unidentified ankylosaur. (See additional comments at Monoclonius and Triceratops.) Ceratopsia Ceratopidae. L. Cret. NA. [nomen dubium (?Triceratops or ?Torosaurus)]
Agilisaurus Peng 1990 "agile lizard"
AJ-i-li-SAWR-us (Lat. agilis "agile, nimble" + Gr. sauros "lizard") (m) "meaning an agile biped animal as indicated by the light structure of the skeleton and the ratios of the limbs." Ornithopoda Hypsilophodontidae M. Jur. China
Agnosphitys Fraser, Padian, Walkden & Davis 2002 "unknown begetter"
ag-noh-SFIE-tis (Gr. agnos "unknown" + Gr. phitys "begetter") (m) named "with reference to the position of the new form relative to the Dinosauria"--depending on how the group Dinosauria is defined, Agnosphitys is either a small primitive meat-eating dinosaur, or a dinosauriform more advanced than herrarasaurs but not a true dinosaur. Agnosphitys was probably around 70 cm (28 in) long and is based on a left ilium (Holotype: VMNH 1745 (Virginia Museum of Natural History, Martinsville, Virginia)), plus referred material (left maxilla with serrated teeth, left and right astragaluses, right humerus, 2 sacral vertebrae, isolated tooth), found in the Late Triassic Cromhall Quarry, Avon, southwest England. In common with true dinosaurs, it has a brevis fossa on the ilium, a semi-perforate acetabulum under the ilium, and a reduced astragulus with an ascending process in its ankle bones; however, it appears to have only 2 sacral vertebrae (true dinosaurs have at least 3 sacral vertebrae). Agnosphitys has more dinosaurian features than Herrarasaurus, a form that also has only 2 sacral vertebrae and that many researchers consider a true dinosaur. However, other researchers dispute definitions of the Dinosauria that would include Herrarasaurus, which they classify as a dinosauriform rather than a true dinosaur--whether Agnosphitys should be a classified a true dinosaur or as a dinosauriform remains a point of debate.
Type Species: Agnosphitys cromhallensis [krom-haw-LEN-sis] Fraser, Padian, Walkden & Davis 2002: "from Cromhall (Quarry)" in England. Dinosauromorpha Dinosauria(?) Late Triassic Europe [added 6-2002]
Agrosaurus Seeley 1891 "wild country lizard" or "hunting lizard"
AG-ro-SAWR-us (Gr. agro- "rural, wild" (from agros "open country, rural land") or "hunting" (from agra "hunting"); both derivations for agro- are found in Greek: agrostes "country dweller" or "hunter"; syagros "wild boar" or "hunter of boars") + Gr. sauros "lizard") (m) for remains of a dinosaur H. Seeley mistakenly thought came from Australia. Seeley did not provide a derivation for the name, which may allude to the then unsettled region of northern Queensland, Australia, where the type specimen supposedly was found in 1844 by members of the HMS Fly expedition, or to the dinosaur's supposed meat-eating habits, indicated by "two laterally compressed claw-phalanges...of the type usual in carnivorous reptiles." Seeley described Agrosaurus as a "theropod" related to Massospondylus--prosauropods were still thought to be carnivores at the time. Recent research (Vickers-Rich, Rich, McNamara & Milner 1999; Benton, Juul, Storrs & Galton 2000) indicates that the type material was in fact found in Durdham Down, Bristol, England, was mislabeled, and actually belongs to the British dinosaur Thecodontosaurus antiquus [= Thecodontosaurus] [revised 5/2000]
Agustinia Bonaparte 1999 "for Agustin (Martinelli)"
ah-goo-STEE-nee-uh (Agustin + -ia) (f) named "to honor the young student Agustin Martinelli, a member of the paleontological team [from the Museo Argentino de Ciencias Naturales of Buenos Aires] and discoverer of the specimen" (early mention of the dinosaur used the name "Augustia," a preoccupied name); for a moderately large armored sauropod from the Early Cretaceous (Aptian) Lohan Cura Formation, Cerro El Leon, near Picun Leufu, southern Neuquen Province, Argentina. Known from a fragmentary skeleton consisting of weathered, incomplete or distorted bones(Holotype: MCF-PVPH-110 (Museum of Plaza Huincul, Neuquen Province)), including 3 dorsal, 6 sacral and 10 caudal vertebrae, right tibia and femur, 5 left metatarsals and 9 dermal ossifications. Agustinia is remarkable for its dorsal armor, somewhat similar to the plates of stegosaurs, but with the flat surfaces of the plates oriented crosswise over the crest of the backbone rather than parallel to the backbone. The armor is complex, with plates consisting of a large body and one or two smaller thicker pieces connected by soft tissue to the main body of the plate and to the expanded top of the vertebrae--Agustinia evidently could move its dorsal armor using muscles under the skin, perhaps for display. At least four types of osteoderms are present, articulating along the top of the transversely expanded neural spines. However, the series of armor plates is incomplete, and the precise arrangement and appearance of these bones is not completely clear at present. Documented elements include: 1) unpaired, narrow leaf-shaped plates (tranverse width 21 cm) that appear to form a single median row along the frontmost section of the vertebral column; 2) unpaired, thin, broad and rectangular plate-like bones with wide triangular projections (possibly the cores of spikes), total transverse length 64 cm, apparently forming a single row over the anterior half of the dorsal vertebrae; 3) paired, elongated, flat or cylindrical spike-like plates that project out to the sides, forming two parallel rows over the posterior dorsal, sacral and possibly anterior caudal vertebrae; 4) elongated osteoderms (up to 80 cm long), bifucated at the proximal end, that projected dorsolaterally.
Given the fragmentary nature of the specimen, the precise classification of Agustinia is difficult to determine. It appears to be sauropod, based on the morphology of the metatarsals, tibia, fibula, and vertebrae--the shape of the neural spines suggests it may be related to the Rebacchisauridae. Type Species: Agustinia ligabuei [lee-gah-BOO-ay-ie] Bonaparte 1999: to honor Dr. Giancarlo Ligabue (from Venice, Italy) "an active philanthropist, who supported the 1997 expedition to Patagonia." Sauropoda Augustiniidae Early Cretaceous (Aptian) SA. [added 12/99]
Alamosaurus Gilmore 1922 "Ojo Alamo (New Mexico) lizard"
AL-a-mo-SAWR-us (Alamo (from Spanish alamo "poplar tree") + Gr. sauros "lizard") (m) named for Ojo Alamo, New Mexico, near where the fossils were first found. Originally described as from the "Ojo Alamo Sandstone," strata now assigned to the Kirtland Shale (Late Cretaceous)--the term "Ojo Alamo Formation" is currently used for Paleocene deposits. Sauropoda Titanosauridae L. Cret. NA.
Albertosaurus Osborn 1905 "Alberta (Canada) lizard"
al-BUHR-to-SAWR-us (Alberta (for Prince Albert, consort of Queen Victoria) + Gr. sauros "lizard") (m) named for Alberta Province, Canada, where the fossils were found. Theropoda Coelurosauria Tyrannosauridae L. Cret. NA.
Alectrosaurus Gilmore 1933 "mateless lizard"
a-LEK-tro-SAWR-us (Gr. alektros "unbedded, unmarried" [by extension, "alone, unrelated"] + Gr. sauros "lizard") (m) referring to the supposed complete taxonomic distinctness of a new theropod dinosaur from "deinodonts" [tyrannosaurs], the typical large carnivorous dinosaurs of the Late Cretaceous. Gilmore (1933) says: "The unusually large size of the humerus and the enormously long claws are so unlike any known Upper Cretaceous deinodont as to at once set the animal off as a new type of theropod dinosaur. The name Alectrosaurus olseni is therefore proposed for its reception." While most of the incomplete skeletal material originally described by Gilmore (hindlimb, pubis) belongs to a small to medium-sized (5-6 meters (16-20 ft.)) tyrannosaurid, the large clawed forelimbs that inspired the name are now thought (Perle, 1977; Mader and Bradley, 1989) to come from an unidentified segnosaur, a type of plant-eating theropod with very large clawed forelimbs. Perle attributed additional material to the genus in 1977; Alectrosaurus would have had relatively small forelimbs like typical tyrannosaurids. (The unusual name Alectrosaurus is NOT derived from Greek alektor "rooster" and does NOT mean "rooster lizard" or "eagle lizard" as stated in some sources.) Type species: Alectrosaurus olseni [OL-sen-ie], for George Olsen of the American Museum of Natural History, who collected the original specimens at Iren Dabasu, Inner Mongolia. Theropoda Coelurosauria Tyrannosauridae L. Cret. CAs.
Aletopelta Ford & Kirkland 2001 "wandering shield"
a-LEE-to-PEL-tuh (Gr. aletes "wandering" + Gr. pelte "shield") (f) named to indicate an armored dinosaur from southern California: "because originally, the [geologic] plate containing the Peninsular Ranges Terrane, where Carlsbad and San Diego, California, are today, was somewhere opposite the middle of Mexico...this plate had thus been wandering northward, carrying the specimen with it." Aletopelta is medium-size (est. around 6 m (20 ft) long) ankylosaurid, known from a partial skeleton (Holotype: SDNHM 33909 (San Diego Natural History Museum, San Diego, California)), including femora, tibiae, fibulae and incomplete parts of a scapula, humerus, ulna, left and right ischium, vertebrae, ribs, partial armor over the pelvic girdle plus at least 60 detached armor plates and 8 teeth, found in the Late Cretaceous (Upper Campanian) marine Point Loma Formation, near Carlsbad, California. Apparently the bloated carcass floated out to sea and formed a miniature reef environment after it sunk to the bottom. Aletopelta is diagnosed as an ankylosaurid mainly based on the shape and arrangement of its osteoderm armor, which is closer in form to ankylosaurids than to nodosaurids. Ben Creisler suggested the name Aletopelta.
Type Species: Aletopelta coombsi [KOHM-zie] Ford & Kirkland 2001: to honor the vertebrate paleontologist Walter P. Coombs, Jr., "for his ground-breaking work on ankylosaurs and his years of research, which have inspired many an enthusiast as well as professional paleontologist." Ankylosauria Ankylosauridae Late Cretaceous (Campanian) NA [added 6-2002]
Algoasaurus Broom 1904 "Algoa Bay (South Africa) lizard"
al-GOH-a-SAWR-us (Algoa (from Portuguese alagoa "lagoon") + Gr. sauros "lizard") (m) named for Algoa Bay, Cape Town, South Africa, near where the fossil was found; Sauropoda E. Cret. SAfr. [nomen dubium]
Alioramus Kurzanov 1985 "other (evolutionary) branch"
AL-ee-o-RAY-mus (Lat. alius "other + Lat. ramus "branch") (m) so-named because it represents a distinct branch of tyrannosaur evolution, retaining some primitive features (a long snout and more teeth). Theropoda Coelurosauria Tyrannosauridae L. Cret. CAs.
Aliwalia Galton 1985 "for Aliwal North"
ahl-i-WAHL-ee-a (Aliwal + -ia) (f) named for Aliwal North, South Africa, near where the fossil was found; the town itself was named to commemorate the British victory at Aliwal, India in 1846. Theropoda ?Herrerasauridae L. Trias. SAf.
Allosaurus Marsh 1877 "strange (vertebra) lizard"
AL-o-SAWR-us (Gr. allos "strange" + Gr. sauros "lizard")* (m) named for its vertebrae. Marsh (1877) says: "distinguished from any known Dinosaurs by the vertebrae which are peculiarly modified to ensure lightness. Although apparently not pneumatic, they have the weight of the centra greatly reduced by deep excavations in the sides," resulting in a constricted shape. The two vertebrae in the fragmentary type specimen were somewhat crushed, however, and later, more complete specimens of Allosaurus showed the centra of the vertebrae had internal cavities typical of other dinosaurs, contrary to Marsh's first impression, although the cavities were probably filled with blood-producing tissue rather than air. The Latin type species name fragilis [FRAJ-i-lis] "fragile" reflects Marsh's observation that the vertebrae "have the centra hour-glass in form, the middle part being so diminished as to greatly reduce the strength." (Allosaurus does not mean "leaping lizard.") Theropoda Carnosauria Allosauridae L. Jur. NA. (?E. Cret. Aus.)
Alocodon Thulborn 1973 "furrowed tooth"
a-LOK-o-don (Gr. alok- (alox) "furrow" + Gr. odon "tooth") (m) named for small ornithopod teeth with vertical grooves. Ornithopoda i.s. L. Jur. Eur. [nomen dubium]
Altirhinus Norman 1998 "high snout"
al-ti-RIEN-us (Lat. altus "high" + Gr. rhin-(rhis) "nose, snout" + -us) (m) named "in recognition of the highly arched nasal bones of the skull which give the snout of this animal a distinctively elevated profile"; for a large (7-8 m. (23-26 ft.)) iguanodont from Khuren Dukh, Dornogov (East Gobi Province), south-central Mongolia, notable for the unusual expanded shape of its snout. The type skull for Altirhinus (PIN 3386/8) has been displayed, referred to and widely illustrated as a dinosaur called "Iguanodon orientalis" Rozhdestvensky 1952. However, the name "Iguanodon orientalis" was originally proposed based on another very incomplete specimen (jaw fragments) from Mongolia that appear to belong to an animal distinct from the new "high-snouted" iguanodont; Norman (1996) considered Rozhdestvensky's type material inadequate to diagnose "Iguanodon orientalis" in a scientifically useful way.
Altirhinus is known from a fairly complete skull, parts of another skull and jaw, and various parts of the skeleton from three adult individuals and two possible juveniles. Some features in Altirhinus parallel those found in later hadrosaurids, such as a large diastema between the beak and the grinding cheek teeth, and extra replacement teeth. The expansion of its nasal cavity may be an adaptation to a seasonally dry climate to help retain moisture using a turbinal system. However, Altirhinus evolved such characters independently, perhaps in response to a dry climate with tough vegetation, and is not considered a direct ancestor to hadrosaurs. In other ways it is a typical iguanodont, with a manus very similar to Iguanodon's, including a "spike" thumb and a prehensile fifth digit.
Type species: Altirhinus kurzanovi [koor-zuh-NOH-vie] "for the collector of this new species, Dr. Sergei M. Kurzanov of the Paleontology Institute of the Russian Academy of Sciences, Moscow, who is renowned for his collecting prowess, and his work on a wide variety of Mongolian fossil vertebrates." Ornithopoda Iguanodontidae E. Cret. (Late Aptian/Albian) Mongolia
Altispinax von Huene 1923 "high spine"
AL-ti-SPIEN-aks (Lat. altus "high" + Lat. spina "spine" + Gr. -ax [animal name suffix]) (m) genus now restricted to a tooth; von Huene proposed the name for both the tooth and a group of "Megalosaurus" vertebrae with high back spines, thus the name. The Greek animal-name ending suffix -ax (as in Platax, Labrax, Scolopax, etc.) is probably by analogy with Cuvier's shark genus Spinax. (See Becklespinax). Theropoda i.s. E. Cret. Eur. [nomen dubium]
Alvarezsaurus Bonparte 1991 "Alvarez's lizard"
AHL-vahr-ez-SAWR-us (D. G. Alvarez + Gr. sauros "lizard") (m) named to honor Don Gregorio Alvarez, noted historian of Neuquén Province, Argentina, where the fossil was found; some researchers (Novas 1994) now classify the genus along with Mononykus as a flightless bird with large hooked forelimbs. Theropoda Alvarezsauria Alvarezsauridae E. Cret. SA.
Alwalkeria Chatterjee & Creisler 1994 "for Alick Walker"
al-wah-KEER-ee-a (Al(ick) + Walker + -ia) (f) named to honor Alick D. Walker, British vertebrate paleontologist, for his valuable contributions to Mesozoic vertebrates. (To replace preoccupied Walkeria Chatterjee). Theropoda i.s. L. Trias. India
Alxasaurus Russell & Dong 1993 "Alxa (Inner Mongolia) lizard"
AHL-shah-SAWR-us (Alxa + Gr. sauros "lizard") named for the Alxa ("Alashan") Desert of Inner Mongolia, China, where the type specimen was found; a primitive "segnosaur." Theropoda Therizinosauroidea Alxasauridae L. Cret. CAs.
Amargasaurus Salgado & Bonaparte 1990 "La Amarga Creek (Argentina) lizard"
ah-MAHR-gah-SAWR-us (Amarga + Gr. sauros "lizard") (m) named for La Amarga Creek, near where the fossil was found in Neuquén Province, Argentina; a form with remarkably long spines on its neck. Sauropoda Dicraeosauridae E. Cret. SA.
Ammosaurus Marsh 1891 "sandstone lizard"
AM-o-SAWR-us (Gr. ammos "sand" + Gr. sauros "lizard") (m) alluding to the Connecticut River Valley sandstones, where the fossil was found. The original specimen was almost complete, but Marsh was only able to save the posterior portion--the anterior part was in a sandstone block used in constructing the South Manchester Bridge in Connecticut. The bridge was demolished in 1969, and researchers at Yale were able to retrieve some additional fossil material. Prosauropoda Plateosauridae E. Jur. NA.
Ampelosaurus Le Loeuff 1995 "vineyard lizard"*
AM-pel-o-SAWR-us (Gr. ampelos "vine" + Gr. sauros "lizard") alluding to the site where the fossils were found: a bone-bed located at the southern end of the Blanquette de Limoux vineyards in Campagne-sur-Aude, south-central France. An armored sauropod 15 m. long. Sauropoda Titanosauridae L. Cret. Eur.
Amphicoelias Cope 1877 "biconcave (vertebrae)"
AM-fi-SEEL-ee-as (Gr. amphi "around, on both sides" + Gr. koilos "hollow, concave" + -ias "in character") (m) named for its dorsal vertebrae. Cope (1877) says: "The centra [of the dorsal vertebrae] differ from those of Camarasaurus in the form of their articular extremities...They are unequally amphicoelous, the posterior extremity being more concave." Marsh (1881) later disputed the diagnostic value of the feature and the validity of Cope's proposed family Amphicoeliidae, because "all the known Sauropoda...have similar vertebrae [near the sacrum], with opisthocoelian centra in the cervical and anterior dorsal region." One extremely large partial dorsal vertebra described by Cope in 1878 under the name A. fragillimus (fra-JIL-i-mus) "very fragile" (in allusion to the unusual thinness of the bone, a feature Cope thought indicated aquatic habits), would have been over eight feet tall if complete, and must have belonged to an animal close to 170 feet in length. Unfortunately, this astonishing specimen is now lost. Amphicoelias remains a poorly known, but possibly diagnosable genus, with newly discovered material yet to be described. Sauropoda Diplodocidae L. Jur. NA
Amphisaurus Marsh 1882 "near lizard"
AM-fi-SAWR-us (Gr. amphi "near, around, both" + Gr. sauros "lizard")* (m) alluding its transitional nature, with supposed affinities to both the primitive Palaeosaurus and later dinosaurs, as discussed by Cope (1870) and others. (To replace preoccupied Megadactylus Hitchcock; preoccupied by Amphisaurus Barkas 1870. See Anchisaurus) [= Anchisaurus]
Amtosaurus Kurzanov & Tumanova 1978 "Amtgay (Mongolia) lizard"
AHM-to-SAWR-us (Amt(gay) + Gr. sauros "lizard") (m) named for the Amtgay site, Omongov Province, southern Mongolia, where the fragmentary skull was found. Originally classified as an ankylosaur, the specimen may be a hadrosaur. ?Ornithopoda ?Hadrosauridae L. Cret. CAs.
Amygdalodon Cabrera 1947 "almond tooth"
am-ig-DAL-o-don (Gr. amygdale "almond" + Gr. odon "tooth") (m) alluding to the oval ("almond") shape of the teeth. Sauropoda Cetiosauridae L. Cret. SA.
Anasazisaurus Hunt & Lucas 1993 "Anasazi lizard"
ahn-ah-SAH-zee-SAWR-us (Anasazi (from Navajo 'anaasazi "ancient ones") + Gr. sauros "lizard") (m) named for the ancient Anasazi people, who lived in Chaco Canyon near the type locality where the fossil was found in New Mexico; for a hook-nosed skull attributed to the species Kritosaurus navajovius by Jack Horner in 1992. Hunt and Lucas considered Kritosaurus a nomen dubium, based on undiagnostic type material, and proposed the new name for a taxon distinguished by "possessing a short, posteriorly folded nasal crest that is above the level of the frontals, but does not extend posterior to the anterior end of the frontals." Ornithopoda Hadrosauridae Hadrosaurinae L. Cret. NA. [= ?Kritosaurus]
Anatosaurus Lull & Wright 1942 "duck lizard"
a-NAT-o-SAWR-us (Lat. anat- (anas) "duck" + Gr. sauros "lizard") (m) referring to the duckbill shape of its snout; for "Claosaurus" annectens Marsh, now classified as Edmontosaurus annectens. [= Edmontosaurus]
Anatotitan Brett-Surman in Chapman & Brett-Surman 1990 "duck titan"
a-NAT-o-TIE-tan (Lat. anat- (anas) "duck" + Gr. Titan, a mythical giant) (m) named for its duckbill snout and great size; formerly called Anatosaurus copei, a species now considered distinct from Edmontosaurus annectens. The new generic name was suggested by Donald Baird. Cope's original type specimen (AMNH #5886) is the source of the popular term "duckbilled dinosaur," a term Cope himself did not use, however. In one of the great dinosaur finds of all time, two of Cope's collectors, J. L. Wortman and R. S. Hill, unearthed a well preserved, almost complete hadrosaur skeleton in the Black Hills of South Dakota in the summer of 1882. The skull and lower jaws were virtually intact, providing the first good evidence for a startling looking creature, quite distinct from the European Iguanodon, the former model for hadrosaurs. Cope's 1883 description of the skull noted in particular the "double spoon-like bill" that formed "a weak spatulate beak." Unfortunately, part of a bone on the inner lower jaw was missing, leading Cope to conclude, in error, that the teeth were only "slightly attached," and that any attempt to eat branches of trees would "have scattered [the teeth] on the floor of the mouth," thus inviting the mistaken notion that hadrosaurs were habitually aquatic dinosaurs designed for dabbling after succulent water plants. Cope called his new Lance age "spoonbill" Diclonius mirabilis, claiming that Leidy had abandoned the generic name Trachodon in 1868. It is not completely clear what taxonomic reasoning led Cope to use Leidy's old Judith River species name mirabilis for the Lance find, or to substitute his own 1876 name Diclonius--another Judith River form based only on teeth--as a synonym of Trachodon. Questionable nomenclature aside, Cope established the key feature of the new animal when he cited various bird resemblances in the skull: "The general form and appearance of the skull, as seen in profile, is a good deal like that of a goose. From above it has more the form of a rather short-billed spoonbill." As early as 1890, however, the German textbook Elemente der Palaeontologie decribed the skull of Cope's Diclonius as resembling "that of a gigantic duck." Cope's original characterization of the genus as a "spoonbill dinosaur" (the popular term used in the famous 1897 Century Magazine article "Strange Creatures of the Past," based on interviews with Cope) was a perfectly apt description for a flat-headed hadrosaur--yet the epithet "spoonbill" never stuck. Cope's famous collection of fossil reptiles was purchased for the American Museum in 1899, including his specimen of the "spoonbill dinosaur." In the meantime, Marsh had made Cope's Diclonius a synonym of Leidy's Hadrosaurus in 1892, a usage that was widely accepted until Hatcher (1902) argued for use of the name Trachodon. The April-May 1901 issue of the American Museum Journal (forerunner to Natural History magazine) carried a letter from the field by Barnum Brown, describing his new dinosaur finds in Wyoming and Montana. An anonymous footnote to the letter identified Hadrosaurus (= Cope's Diclonius) as the "Duck-billed dinosaur." This footnote seems to be the earliest published use of the term (in English, at least), and indicates that staff at the American Museum already favored "duckbilled dinosaur" over Cope's original term "spoonbill dinosaur," perhaps by analogy with "duckbilled platypus." The celebrated mounted pair of specimens in the American Museum made the "duckbilled dinosaur" world famous, although the official scientific name assigned the form was variously cited over the years as Diclonius mirabilis, Hadrosaurus mirabilis, Trachodon mirabilis, Claosaurus annectens, Trachodon annectens, Thespesius annectens, Anatosaurus copei, Anatosaurus annectens, Edmontosaurus annectens, and, finally, Anatotitan copei! The nontechnical term "duckbilled dinosaur" later was adopted to refer to all varieties of hadrosaurs. Ornithopoda Hadrosauridae Hadrosaurinae L. Cret. NA.
Anchiceratops Brown 1914 "near horned face" ("intermediate (frill) horned face")
ANG-ki-SER-a-tops (Gr. agkhi "near, close" + Gr. kerat- (keras) "horn" + Gr. ops "face") (m) named for its supposed close affinity to both Centrosaurus (which Brown called Monoclonius) and Triceratops as "one more link in the morphological chain by which the ceratopsian crest has been developed," with a squamosal "intermediate in length between Monoclonius and Triceratops." According to Brown, "If we compare a series of skulls of Monoclonius, Anchiceratops and Triceratops, representing respectively the succeeding geological formations, Judith River, Edmonton and Lance, the squamosals are to seen to lengthen in each succeeding type and the lateral fontanelles, which were very large in Monoclonius, are much reduced in Anchiceratops, and have entirely disappeared in Triceratops. Thus we see a gradual backward extension of the squamosal with a lateral expansion of the central part of the crest." Brown's analysis is contrary to the modern understanding of ceratopsian evolution--Centrosaurus belongs to a different subfamily (Centrosaurinae), and is not closely related to Anchiceratops or Triceratops, which belong to the Chasmosaurinae. Ceratopsia Ceratopidae Chasmosaurinae L. Cret. NA.
Anchisaurus Marsh 1885 "near lizard"
ANG-ki-SAWR-us (Gr. agkhi "near" + Gr. sauros "lizard")* (m) named to indicate its supposed primitive intermediate nature, between ancestral forms and later dinosaurs. Originally described by Marsh as "one of the oldest known members of the Theropoda," the dinosaur has been reclassified as a herbivorous prosauropod, and redated from the Late Triassic to the Early Jurassic. The type specimen was originally called Megadactylus polyzelus E. Hitchcock Jr. 1865, the generic name being preoccupied. The type species name polyzelus (Gr. polyzelos) po-li-ZEE-lus "much coveted" was chosen, as Hitchcock explains: "in allusion to the fact that for so many years other remains than simply tracks of the former inhabitants of the Connecticut valley have been eagerly and anxiously sought for, and that now we have the much coveted bones." (To replace the preoccupied name Amphisaurus Marsh, with a similar meaning.) Prosauropoda Anchisauridae E. Jur. NA. (?CAs. ?SAfr.)
Andesaurus Calvo & Bonaparte 1990 "Andes Mountains lizard"
AN-de-SAWR-us (Andes + Gr. sauros "lizard") (m) named for the Andes Mountains, a geographic feature near the region where the fossil was found in Neuquén Province, Argentina (Rio Limay Formation). Sauropoda Titanosauria Andesauridae E. Cret. SA.
Angaturama Kellner & Campos 1996 "noble one"
AHN-gah-too-RAH-ma (Tupi Indian angaturama "noble, brave") (m) named for Angaturama, a protective spirit in the aboriginal Tupi Indian culture of Brazil; proposed for a large, narrow-snouted, probably fish-eating theropod from Araripe Basin, northeastern Brazil, a region where the Tupi lived. Theropoda Spinosauridae E. Cret. SA. (Brazil)
Animantarx Carpenter, Kirkland, Burge & Bird 1999 "living fortress"
an-i-MAN-tahrks (Lat. animant-animans) "living" + Lat. arx "fortress, citadel")* (f) named based on Richard Swann Lull's observation regarding ankylosaurs, that as "an animated citadel, these animals must have been practically unassailable..." (Lull 1914). Animantarx is a medium-sized Pawpawsaurus-like nodosaurid, known from a partial skull and right mandible, and a partial skeleton, including vertebrae, ribs, both scapula-coracoids, humerus, femur and left ilium with ischium (Holotype: CEUM 6228R (Prehistoric Museum, College of Eastern Utah)); found in the Cedar Mountain Formation (Mussentuchit Member), eastern Utah. Animantarx has a high-domed cranium, very small post-orbital "horns," small quadratojugal "horn," and an elongated coracoid about 63% the length of the scapula. Skull is estimated at 25 cm (10 in.) long, suggesting the entire animal was about 2.8-3 m (9-10 ft.) long. The generic name was suggested by Ben Creisler.
Type Species: Animantarx ramaljonesi [RAM-al-JOHNZ-ie] Carpenter, Kirkland, Burge & Bird 1999: for "Ramal Jones, who discovered the specimen using a modified scintillometer in an area with no bones exposed". Ankylosauria Nodosauridae Early Cretaceous (Albian-enomanian)NA. [added 10/99]
Ankylosauria Osborn 1923 "fused lizards"
ANG-ki-lo-SAWR-ee-a (Gr. agkylos "bent, crooked" [with the applied anatomical meaning "stiff" or "fused" as in "ankylosed," "ankylosis"] + Gr. sauros "lizard" + -ia) (n) [taxon]
Ankylosaurus Brown 1908 "fused lizard"
ANG-ki-lo-SAWR-us (c.u.: ang-KIE-lo-SAWR-us) (Gr. agkylos "bent, crooked" [with the applied anatomical meaning "stiff" or "fused" as in "ankylosed," "ankylosis"] + Gr. sauros "lizard") (m) alluding to a range of anatomical features in which bones have coossified or fused together: the skull has "plates coossified in a continuous surface over the top and sides of the skull"; the massive scapula and coracoid are "coossified and curved"; the four posterior dorsal ribs "are firmly coossified to the vertebrae" to form "a rigid framework for the support of the dermal armor;" and the armor itself has plates "coossified to heavy bone" that "represent part of a continuous shield" covering "part of the posterior dorsal or pelvic region." The 1908 type material was missing both the coossified overlapping caudal vertebrae and the massive club of fused dermal plates at the tip of the tail, however. Brown characterized the family Ankylosauridae as having the "backbone stiff," and noted the wide, bowed shape of the animal's ribs and its supposed "strongly arched" back (an error based on a presumed resemblance to stegosaurs and glyptodonts--ankylosaurs had rather flat backs); thus, the additional meanings "stiff lizard" and "curved lizard" probably should be read in the name Ankylosaurus as well. Ankylosauria Ankylosauridae L. Cret. NA.
Anodontosaurus Sternberg 1929 "toothless lizard"
an-o-DONT-o-SAWR-us (Gr. an- "not, without" + Gr. odont- (odous) "tooth" + Gr. sauros "lizard") (m) named to indicate the supposed "first toothless member of the Stegosauria to be recorded." Only the front of the jaws was actually toothless, however. [= Dyoplosaurus]
Anoplosaurus Seeley 1878 "unarmored lizard"
AN-o-plo-SAWR-us (Gr. an- "not, without" + Gr. hoplon "weapon, shield" + Gr. sauros "lizard") (m) probably referring to its lack of armor compared to other dinosaurs described in the same 1878 paper. Ornithopoda Iguanodontidae E. Cret. Eur. [nomen dubium]
Anserimimus Barsold 1988 "goose mimic"
AN-ser-i-MIEM-us (Lat. anser "goose" + Gr. mimos "mimic") (m) named for its birdlike appearance, by analogy with other ornithomimid names derived from birds; distinguished by its stongly constructed forelimbs. Theropoda Ornithomimosauria Ornithomimidae L. Cret. CAs.
Antarctosaurus von Huene 1927 "southern lizard"
an-TARK-to-SAWR-us (Gr. ant- (anti) "opposite" + Gr. arktos "north" + Gr. sauros "lizard") (m) referring to South America (NOT Antarctica), where the fossil was found in Argentina. Sauropoda Titanosauridae L. Cret. SA.
Antrodemus Leidy 1870 "cavity-bodied (vertebra)"
an-TROD-e-mus (Gr. antron "cave" (commonly used in anatomy in the Latin form antrum to mean "a cavity or chamber, especially one in bone" (American Heritage Dictionary, 1995 edition) + Gr. demas "body" + -us) (m) Leidy proposed the name Antrodemus in 1870 (Proceedings of the Academy of Natural Sciences of Philadelphia, 22: 3-4)) based on a half of a centrum from a tail vertebra found in Colorado. He originally attributed the bone to a new species of the European genus Poekilopleuron: "One of the most remarkable characters of Poicilopleuron [sic] is the presence of a large medullary cavity within the bodies of the vertebrae...The same character is presented by the Colorado fossil." According to Leidy, the Colorado partial vertebra indicated an animal "one-third greater" in size than the European species Poekilopleuron bucklandii. He concluded: "The species represented by the fossil may be called Poicilopleuron valens [Latin for "strong," after its larger size]. Should the division of the medullary cavity of the vertebral body into smaller recesses by trabeculae by significant of other characters indicating the Colorado saurian to be distinct from Poicilopleuron, it might be named Antrodemus." His repeated use of the terms "cavity" and "vertebral body" throughout his description would have made the meaning of the name Antrodemus obvious to his classically educated colleagues such as Edward Drinker Cope or Richard Owen.
Leidy correctly surmised that the animal was a dinosaur rather than a crocodile, but with such meager type material, other authors paid little attention to Leidy's taxon. Lucas (cited in Hay 1909) proposed that Antrodemus was the same as Marsh's Labrosaurus, though the basis for this identification was not made clear. Gilmore (1920) reexamined the type specimen and argued that Antrodemus was indistinguisable from Allosaurus--thus Leidy's older name should be used as the valid name. Various authors used either the name Antrodemus or Allosaurus into the 1960s. However, Madsen (1976) reviewed Allosaurus, and concluded that Antrodemus was based on undiagnostic material, rendering Leidy's generic name a nomen dubium. All modern authors now recognize Allosaurus as the valid name. (The name Antrodemus does NOT mean "cave demon" and is NOT the name of the devil in Greek mythology, contrary to a few recent authors. Neither does the name mean "strongly framed," as some books indicate. There is no basis in Greek or Latin, or scientific usage, for any of these other interpretations.) Theropoda Carnosauria Allosauridae L. Jur. NA [nomen dubium (?Allosaurus)]
Apatodon Marsh 1877 "deceptive tooth"
a-PAT-o-don (Gr. apatao "deceive" + Gr. odon "tooth")* (m) named for what Marsh thought was "a portion of a lower jaw" of an animal with a tooth deceptively resembling "in form and superior surface of the crown, that of a typical Suilline [pig]." Georg Baur later reidentified the specimen as part of a weathered dinosaur vertebra--the supposed "teeth" were only a chance pattern in an eroded neural spine. Specimen now lost. [= ?Allosaurus]
Apatosaurus Marsh 1877 "deceptive (chevron) lizard"
a-PAT-o-SAWR-us (t.L.m.: AP-a-to-SAWR-us) (Gr. apatao "deceive" + Gr. sauros "lizard")* (m) alluding to the Y-shaped chevrons (or hemal arches) on the underside of the tail, which Marsh thought were deceptively like those found in some mosasaurs (Tylosaurus, Platcarpus, etc.) in which the chevrons were not fused to the centra of the vertebrae: "The chevron bones differ from those of most known Dinosaurs in having the superior articular ends of the rami not united, but separated from each other, as in the Mosasauria with free haemapophyses." The specimen had not been prepared when Marsh published the name and description, and his quick-and-dirty comparison with mosasaurs now seems odd and obscure--chevrons at the near-end of the tail in Apatosaurus were bridged at the top to form a compressed triangle on a stem, perforated by a hemal canal, as in many other dinosaurs, while some mosasaurs (Mosasaurus, Clidastes, etc.) had chevrons fused directly to the centra of the caudal vertebrae, unlike in Apatosaurus. (See additional comments at Brontosaurus.) (Apatosaurus does not mean "headless lizard.") Sauropoda Diplodocidae L. Jur. NA.
Aragosaurus Sanz, Buscalioni, Casanovi & Santafe 1987 "Aragón (Spain) lizard"
AHR-a-go-SAWR-us (Aragón + Gr. sauros "lizard") (m) named for Aragon Province, Spain, where the fossil was found. Sauropoda Camarasauridae E. Cret. Eur.
Aralosaurus Rozhdestvensky 1968 "Aral Sea lizard"
AR-a-lo-SAWR-us (Aral + Gr. sauros "lizard") (m) named for Aral Sea, the huge inland lake near where the fossil was found in central Kazazhstan. Ornithopoda Hadrosauridae Hadrosaurinae L. Cret. CAs.
Archaeoceratops Dong & Azuma 1996 "ancient horned-face"
AHR-kee-o-SER-a-tops (Gr. arkhaios "ancient" + Gr. kerat- (keras) "horn" + Gr. ops "face") (m) named to indicate "the primitive nature of the animal, which is the oldest known neoceratopsian." For a small (88-90 cm. (1 yd.) long), lightly built, bipedal ceratopsian, known from two incomplete skeletons and a relatively well-preserved skull, found in the Xinminbao Group, Gongpoquan Basin of the Mazongshan Area of Gansu Province, north central China. The relatively long skull (18.8 cm.) has no trace of a nasal or of frontal horn cores, and only has a very short and shallow "frill" formed along the back by the squamosals and parietals. The teeth are highly unusual in that they contrast between the lower and upper jaws: the dentary teeth (lower jaw) are similar to those of the ornithopods (low crown with small denticles), whereas the maxillary teeth (upper jaw) are larger and more like those of protoceratopsians (with a strong longitudinal ridge). Type species: Archaeoceratops oshimai [oh-shee-MAH-ie] "for Oshima," named for "Mr. Oshima, the director of the Chunichi-Shinbun of Japan, who supported the Sino-Japan Silk Road Dinosaur Expedition." Neoceratopsia Archaeoceratopidae E. Cret. CAs. (China).
Archaeopteryx von Meyer 1861 "ancient wing"
AHR-kee-OP-ter-iks (Gr. arkhaios "ancient" + Gr. pteryx "wing, feather") (f) Von Meyer first mentioned a fossil feather from the Jurassic Solnhofen deposits in a letter published in August, 1861. He described the find as either a flight or tail quill preserved in rock typical of the lithographic slates, though he was not completely convinced that the specimen came from the Mesozoic, since no bird fossils earlier than the Tertiary were then known. He did not propose a name for the isolated feather. In a follow-up letter published in September, 1861, after personal investigations, he confirmed that the feather was a genuine fossil from Jurassic deposits at Solnhofen. He also cited news that a nearly complete skeleton of a feather-bearing animal (now known as the "London specimen") had recently been found in the same lithographic quarries. In a slightly ambiguously worded passage, he gave "the animal" the name Archaeopteryx lithographica (lith-o-GRAF-i-ka, for the lithographic slates), the usual assumption being that the "animal" he intended to name was the source of his feather rather than the newly found "feather-bearing animal" whose specimen he apparently had not seen yet in person. In a fuller description of the feather published some months later, he took a cautious approach to exactly what sort of animal was the source of his feather, and was typically reluctant to conclude that the animal was a true bird, being a skeptical opponent of Cuvier's theories concerning the "correlation of parts." He did propose, however, that the feather came from an animal similar to the still formally undescribed and unnamed "feather-bearing animal." His German colleague J. A. Wagner gave a first description of the "feather-bearing animal" in 1861, proposing the name Griphosaurus "enigma lizard," although he only had seen a drawing, and not the specimen itself. The modern usage of the name Archaeopteryx was established by Richard Owen in 1863, when the "London specimen" was purchased by the British Museum. Owen accepted Cuvier's "law of correlation," and had no hesitation about identifying the feathered animal as a true bird. He also accepted von Meyer's generic name Archaeopteryx for the skeletal specimen with feathers, but thought a more appropriate species name would be macrura "long-tail" [mak-ROOR-a] in as much as this feature was highly distinctive--he reasoned that von Meyer's original species A. lithographica, based on a single feather, might well have been a short-tailed form, just as both long-tailed and short-tailed pterosaurs were known from the lithographic slates. Confusion over the correct type specimen and type species name was settled by an official decision of the International Commission on Zoological Nomenclature in 1964, which made the "London specimen" the holotype and Archaeopteryx lithographica the valid name. Although von Meyer did not specify if he intended Archaeopteryx to mean "ancient feather" or "ancient wing," the interpretation "ancient wing" is preferable, based on the standard usage of pteryx as "wing" for bird names in zoological nomenclature (Apteryx, etc.). It also would be consistent with the modern scientific usage of Archaeopteryx as defined by Owen. Von Meyer, moreover, accepted Owen's usage of the name for the "London specimen" (in Evans, 1865), although he still refused to recognize the animal as a true bird. Wellnhoffer (1993) has described a second slightly younger species (Archaeopteryx bavarica ba-VAR-i-ka "Bavarian") from a seventh specimen discovered at Solnhofen in 1992, distinguished by an ossified sternum and interdental plates in the jaws. (Placed on the Official List of Generic Names in Zoology with Name No. 1433 by ICZN Opinion # 607 based on the British Museum holotype.) Archaeopterygiformes Archaeopterygidae L. Jur. Eur. [dino-bird]
Archaeornis Petronievics in Petronievics & Woodward 1917 "ancient bird"
AHR-kee-OR-nis (Gr. arkhaios "ancient" + Gr. ornis "bird") (m) name proposed for the "Berlin specimen," found at Eichstätt; described as representing a genus supposedly distinct from the London specimen of Archaeopteryx. Reseachers now think Archaeopteryx had indeterminate growth more typical of reptiles, rather than the combination of rapid juvenile growth with a fixed adult size characteristic of modern birds, and that the minor differences between the London and Berlin specimens do not merit taxonomic separation. [= Archaeopteryx]
Archaeornithoides Elzanowski & Wellnhofer 1992 "Archaeornis-like (dinosaur)"
AHR-kee-OR-ni-THOI-deez (t.L.m.: AHR-kee-or-NITH-o-IE-deez) (from Archaeornis "ancient bird" [junior synonym of Archeopteryx] + -oides "resembling")* (m) named for a resemblance to primitive toothed birds: "The avian features of the maxillary palatal shelf and dentition distinguish Archaeornithoides from all other potential sister-groups of birds, suggesting that Archaeornithoides is the closest known theropod relative of birds." A juvenile specimen. Theropoda Archaeornithoididae L. Cret. (Mongolia)
Archaeornithomimus Russell 1972 "ancient ornithomimid"
AHR-kee-or-NITH-o-MIEM-us (Gr. arkhaios "ancient" + Ornithomimus (Gr. ornith- (ornis) "bird" + Gr. mimos "mimic")) (m) new name proposed for "`Ornithomimus' asiaticus, from the Iren Dabasu Formation of Mongolia [which] is more primitive than...later Canadian forms.." Theropoda Ornithomimosauria Ornithomimidae L. Cret. CAs.
Arctometatarsalia Holz 1994 "compressed metatarsals"
ARK-to-MET-a-tar-SAY-lee-a (from Lat. arctus "narrow, compressed" + Gr. meta "beyond" + Gr. tarsos "tarus" + Lat. -alis) (n) Proposed as a clade within the Coelurosauria in which members have feet with a third metatarsal pinched at the top, and buttressed against the second and fourth metatarsal to form a tightly bound structure, adapted to rapid locomotion. Some researchers believe this feature developed independently in different groups of theropods (Elmisauridae, Avimimus) and that the Arctometatarsalia are not a natural group. Addresssing this problem, Holz (1996) redefined the Arctometatarsalia as "a clade composed of Ornithomimus and all theropods sharing a more recent common ancestor with Ornithomimus than with birds." [clade]
Argentinosaurus Bonaparte & Coria 1993 "Argentine lizard"
ahr-jen-TEEN-o-SAWR-us (Argentina + Gr. sauros "lizard") (m) named for Argentina; a huge sauropod (30 m. +) from the Rio Limay formation, Neuquén Province, Argentina. Sauropoda Titanosauria Andesauridae L. Cret. SA.
Argyrosaurus Lydekker 1893 "silver lizard"
AHR-ji-ro-SAWR-us (Gr. argyros "silver" + Gr. sauros "lizard") (m) alluding to Argentina "land of silver," where the fossils were found. Sauropoda Titanosauridae L. Cret. SA.
Aristosaurus Hoepen 1920 "best (specimen) lizard"
a-RIS-to-SAWR-us (Gr. aristos "best" + Gr. sauros "lizard") (m) alluding to the preservation of the fossil; "one of [the Transvaal Museum's] best specimens...a nearly complete skeleton." [= Massospondylus]
Aristosuchus Seeley 1887 "superior crocodile"
a-RIS-to-SOOK-us (Gr. aristos "best, superior" + Gr. soukhos "crocodile") (m) named for a kind of reptile Seeley originally considered distinct from both dinosaurs and crocodiles, though with some features of both; based on a specimen named Calamospondylus by Fox in 1866, a name now generally considered a nomen nudum. Theropoda E. Cret. Eur. (Isle of Wight, England)
Arrhinoceratops Parks 1925 "hornless-snout face"
a-RIEN-o-SER-a-tops (Gr. a- "not, without" + Gr. rhin- (rhis) "nose, snout" + Gr. kerat- (keras) "horn" + Gr. ops "face") (m) named to indicate the supposed lack of the nasal horn typical of other large ceratopsians: "The nasal horn core is apparently absent, but the nasal bone is sharp above and somewhat rugose, suggesting that it may have carried a horny sheath." Ceratopsia Ceratopidae Chasmosaurinae L. Cret. NA.
Arstanosaurus Suslov & Shilin 1982 "Arstan (Kazakhstan) lizard"
ahr-stahn-o-SAWR-us (Arstan + Gr. sauros "lizard") (m) named for the ancient Arstan well and benchmark of the same name close to the fossil locality in Kazakhstan. Ceratopsia Ceratopidae i.s. L. Cret. CAs. (Kazakhstan)
Asiaceratops Nessov & Kaznyshkina 1989 "Asian horned face"
AY-zha-SER-a-tops (Gr. Asia + Gr. kerat- (keras) "horn" + Gr. ops "face") (m) named to indicate a form found in Kazakhstan in Central Asia. Ceratopsia Protoceratopidae L. Cret. CAs (Kazakhstan)
Asiamericana Nessov 1995 "Asiamerican (tooth)"
AY-zha-MER-i-KAHN-a (Gr. Asia "Asia" + New Lat. America "America" + -ana) (f) alluding to the occurrence of similar fossil teeth in Central Asia and North America, regions forming a connected land mass during the Cretaceous referred to as "Asiamerica"; based on three teeth found in the central Kyzylkum desert, Uzbekistan, comparable to other teeth found in Kazakhstan and North America that have been illustrated but not formally described. NOTE: Nessov cautions that these unusual teeth may belong to saurodont fish rather than to dinosaurs. ?Theropoda ?Spinosauridae L. Cret. CAs. (Uzbekistan)
Asiatosaurus Osborn 1924 "Asiatic lizard"
ay-zhee-AT-o-SAWR-us (from Gr. Asia "Asia" + Gr. sauros "lizard")* (m) named to indicate Camarasaurus-like teeth found in Ovorkhangai, Mongolia, in Asia. Sauropoda E. Cret. CAs. (China, Monogolia) [nomen dubium]
Astrodon Johnston in Leidy 1865 "star tooth"
AS-tro-don (Gr. astron "constellation, star" + Gr. odon "tooth") (m) In 1859 Dr. C. Johnston briefly mentioned the teeth of a "thecodont saurian" he named Astrodon in a paper on the teeth of Hadrosaurus, but provided no description. He sectioned one tooth for viewing under a microscope, and the name Astrodon alludes to the rather starburst-like "multitude of minute tubuli radiating from the narrow elliptical section of the pulp cavity" as later described and illustrated by Leidy. The external form of the teeth was spoon-shaped, typical of brachiosaurids. Treated by some researchers as a valid senior synonym of Pleurocoelus. Sauropoda Brachiosauridae E. Cret. NA [nomen dubium (?Pleurocoelus)]
Atlantosaurus Marsh 1877 "Atlas lizard"
at-LAN-to-SAWR-us (Gr. Atlant- (Atlas), a mythical Titan + Gr. sauros "lizard") (m) named for its huge size; to replaced preoccupied Titanosaurus Marsh 1877. Sauropoda Diplodocidae L. Jur. NA. [nomen dubium (?Apatosaurus)]
Atlasaurus Monbaron, Russell & Taquet 1999 "Atlas lizard"
AT-luh-SAWR-us (Atlas, a giant who held up the heavens according to Greek mythology + Gr. sauros "lizard") (m) named for the type location in the Atlas Mountains of Morocco (spot at which the Titan Atlas was said to hold up the heavens), and for the animal's gigantic size. Atlasaurus is a moderately large (about 15 m (50 ft) long) sauropod, known from a nearly complete skeleton with skull found at Wawmda, in the Middle Jurassic (Bathonian-Callovian) Tiougguit Formation, Azilal Province, High Atlas of Morocco. A relatively primitive sauropod identified as a "cetiosaur" when first discovered in 1981, Atlasaurus appears to be closer to Brachiosaurus than to any other known sauropod based on detailed similarities between the vertebral column and limbs. It differs from Brachiosaurus, relative to the estimated length of the dorsal vertebral column (assuming 12 vertebrae, 3.04 m)), in having a proportionately larger skull, a shorter neck (with at least 13 cervical vertebrae, shorter and more uniform in length than in Brachiosaurus), a longer tail and more elongated limbs (humerus to femur ratio: 0.99; ulna to tibia ratio: 1.15). The lower jaw is about 69 cm long; the neck about 3.86 m long; humerus 1.95 m long; femur about 2 m long; total estimated length: around 15 m (50 ft); estimated weight: 22.5 metric tons. The teeth are spoon-shaped and have denticles.
Type Species: Atlasaurus imelakei [ee-me-LAH-kay-ie] Monbaron, Russell & Taquet 1999: from Arabic Imelake, name of a giant; for a large animal found in North Africa. Sauropoda Eusauropoda Middle Jurassic (Bathonian-Callovian) NAfr. [added 11/99]
Atlascopcosaurus Rich & Rich 1989 "Atlas Copco lizard"
AT-las-KOP-ko-SAWR-us (Atlas Copco + Gr. sauros "lizard") (m) named for the Atlas Copco Corporation, which supplied pneumatic tools and accessory equipment that enabled the excavations at Dinosaur Cove, Queensland, Australia, where the fossils were found. Ornithopoda Hypsilophodontidae E. Cret. Aus.
Aublysodon Leidy 1868 "backward-flowing (?) tooth"
aw-BLIS-o-don (Gr. au "back, backwards; again; contrariwise" + Gr. blys- (blyzo) "flow, spout forth" + Gr. odon "tooth") (m) Leidy did not provide a derivation or explanation for the name, which may allude to what he noted as the "quite peculiar" form of the teeth: the two cutting edges (carinae) are shifted to the backside to give a semi-cylindrical D-shaped cross section, contrasting with the blade-like front-and-back placement of the cutting edges in Megalosaurus teeth. Leidy proposed the name Aublysodon for three D-shaped teeth, two serrated and one unserrated, that he had previously included with some reservation in the type specimen of Deinodon horridus. (See Deinodon.) Ken Carpenter designated the single unserrated tooth as the lectotype of Aublysodon mirandus in 1982. A number of isolated teeth and two incomplete specimens of carnivorous dinosaurs found with unserrated premaxillary teeth are currently attributed to the genus. Not all researchers agree that the type tooth is diagnostic, however, and the name Stygivenator recently has been proposed for the so-called "Jordan theropod," found in Montana, and generally identified as Aublysodon. (Aublysodon is not a misspelling of "Amblyodon" "blunt-tooth" as sometimes suggested; Leidy or his colleagues would have noted and corrected such an obvious error according to 19th-century nomenclatural practices. If the interpretation of the name proposed here is accurate, Leidy may have formed the unusual combination aublys- by analogy with Greek verbs such as apoblyzo (stem apoblys-) "flow forth," anablyzo (stem anablys-) "spout upwards," katablyzo (stem katablys-) "pour down," etc., and aueryo "pull backwards" (explained incorrectly as au "backwards" + eryo "drag, pull" in 19th century editions of Greek lexicons). The meaning "back, backwards" (= Latin retro, rursus) for Greek au is rejected by modern classical scholars, although that definition was listed in most 19th century Greek lexicons and grammar books available to Leidy.) Theropoda Coelurosauria Tyrannosauridae L. Cret. NA. [?nomen dubium]
Austrosaurus Longman 1933 "southern lizard"
AWS-tro-SAWR-us (Lat. austr- (auster) "south" + Gr. sauros "lizard") (m) alluding to the Southern Hemisphere continent of Australia, where the fossil was found in the state of Queensland. Sauropoda ?Cetiosauridae E. Cret. Aus.
Avaceratops Dodson 1986 "Ava's horned face"
AY-va-SER-a-tops (Ava + Gr. kerat- (keras) "horn" + Gr. ops "face") (m) named to honor Ava Cole, a fine collector of fossils and wife of Eddie Cole, discoverer of the fossil site in Montana. Ceratopsia Ceratopidae Centrosaurinae L. Cret. NA.
Avetheropoda Paul 1988 "bird theropods"
AY-ve-thee-ROP-o-da (Lat. aves "birds" + Gr. ther "beast" + Gr. pod- (pous) "foot" + -a) (n) A taxon proposed to include advanced theropods (including allosaurs) and birds. [taxon]
Avimimus Kurzanov 1981 "bird mimic"
AY-vi-MIEM-us (Lat. avis "bird" + Gr. mimos "mimic") (m) named for the birdlike appearance of the braincase and other features of the skeleton. It is possible that some attributed skeletal remains are a chimaera, mixing together remains of other small theropods. Theropoda Avimimidae L. Cret. CAs.
Avipes von Huene 1932 "bird foot"
AY-vi-pees (Lat. avis "bird" + Lat. pes "foot") (m) named for the fused metatarsals in its foot, a birdlike feature. Theropoda L. Trias. Eur. [nomen dubium]
Azendohsaurus Dutuit 1972 "Azendoh (Morocco) lizard"
ah-ZEN-do-SAWR-us (Azendoh + Gr. sauros "lizard") (m) named for the village of Azendoh, near the fossil deposit in the Atlas Mountains region of Marrakesh, Morocco. Prosauropoda i.s. L. Trias. NAf.