Deinosuchus | |
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Reconstructed D. hatcheri skeleton at the Natural History Museum of Utah | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Clade: | Archosauromorpha |
Clade: | Archosauriformes |
Order: | Crocodilia |
Superfamily: | Alligatoroidea |
Genus: | † Deinosuchus Holland, 1909 |
Type species | |
†Deinosuchus hatcheri Holland, 1909 | |
Other species | |
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Synonyms | |
Deinosuchus ( /ˌdaɪnəˈsjuːkəs/ ) is an extinct genus of alligatoroid crocodilian, related to modern alligators and caimans, that lived 82 to 73 million years ago (Ma), during the late Cretaceous period. The name translates as "terrible crocodile" and is derived from the Greek deinos (δεινός), "terrible", and soukhos (σοῦχος), "crocodile". The first remains were discovered in North Carolina (United States) in the 1850s; the genus was named and described in 1909. Additional fragments were discovered in the 1940s and were later incorporated into an influential, though inaccurate, skull reconstruction at the American Museum of Natural History. Knowledge of Deinosuchus remains incomplete, but better cranial material found in recent years has expanded scientific understanding of this massive predator.
Although Deinosuchus was far larger than any modern crocodile or alligator, with the largest adults measuring 10.6 meters (35 ft) in total length, its overall appearance was fairly similar to its smaller relatives. It had large, robust teeth built for crushing, and its back was covered with thick hemispherical osteoderms. One study indicated Deinosuchus may have lived for up to 50 years, growing at a rate similar to that of modern crocodilians, but maintaining this growth over a much longer time.
Deinosuchus fossils have been described from 10 U.S. states, including Texas, Montana, and many along the East Coast. Fossils have also been found in northern Mexico. It lived on both sides of the Western Interior Seaway, and was an opportunistic apex predator in the coastal regions of eastern North America. Deinosuchus reached its largest size in its western habitat, but the eastern populations were far more abundant. Opinion remains divided as to whether these two populations represent separate species. Deinosuchus was probably capable of killing and eating large dinosaurs. It may have also fed upon sea turtles, fish, and other aquatic and terrestrial prey.
In 1858, geologist Ebenezer Emmons described two large fossil teeth found in Bladen County, North Carolina. Emmons assigned these teeth to Polyptychodon , which he then believed to be "a genus of crocodilian reptiles". [3] Later discoveries showed that Polyptychodon was actually a pliosaur, a type of marine reptile. [4] The teeth described by Emmons were thick, slightly curved, and covered with vertically grooved enamel; he assigned them a new species name, P. rugosus. [3] Although not initially recognized as such, these teeth were probably the first Deinosuchus remains to be scientifically described. Another large tooth that likely came from Deinosuchus, discovered in neighboring Sampson County, was named Polydectes biturgidus by Edward Drinker Cope in 1869. [4]
In 1903, at Willow Creek, Montana, several fossil osteoderms were discovered "lying upon the surface of the soil" by John Bell Hatcher and T.W. Stanton. These osteoderms were initially attributed to the ankylosaurid dinosaur Euoplocephalus . Excavation at the site, carried out by W.H. Utterback, yielded further fossils, including additional osteoderms, as well as vertebrae, ribs, and a pubis. When these specimens were examined, it became clear that they belonged to a large crocodilian and not a dinosaur; upon learning this, Hatcher "immediately lost interest" in the material. After Hatcher died in 1904, his colleague W. J. Holland studied and described the fossils. Holland assigned these specimens to a new genus and species, Deinosuchus hatcheri, in 1909. Deinosuchus comes from the Greek δεινός/deinos, meaning "terrible", and σοῦχος/suchos, meaning "crocodile". [5]
A 1940 expedition by the American Museum of Natural History yielded more fossils of giant crocodilians, this time from Big Bend National Park in Texas. These specimens were described by Edwin H. Colbert and Roland T. Bird in 1954, under the name Phobosuchus riograndensis. Donald Baird and Jack Horner later assigned the Big Bend remains to Deinosuchus, which has been accepted by most modern authorities. [4] [6] The genus name Phobosuchus, which was initially created by Baron Franz Nopcsa in 1924, has since been discarded because it contained a variety of different crocodilian species that turned out to not be closely related to each other. [4]
The American Museum of Natural History incorporated the skull and jaw fragments into a plaster restoration, modeled after the present-day Cuban crocodile. Colbert and Bird stated this was a "conservative" reconstruction, since an even greater length could have been obtained if a long-skulled modern species, such as the saltwater crocodile had been used as the template. [7] Because it was not then known that Deinosuchus had a broad snout, Colbert and Bird miscalculated the proportions of the skull, and the reconstruction greatly exaggerated its overall width and length. Despite its inaccuracies, the reconstructed skull became the best-known specimen of Deinosuchus, and brought public attention to this giant crocodilian for the first time. [4]
Numerous additional specimens of Deinosuchus were discovered over the next several decades. Most were quite fragmentary, but they expanded knowledge of the giant predator's geographic range. As noted by Chris Brochu, the osteoderms are distinctive enough that even "bone granola" can adequately confirm the presence of Deinosuchus. [4] [8] Better cranial material was also found; by 2002, David R. Schwimmer was able to create a composite computer reconstruction of 90% of the skull. [9] [10]
Since the discovery of the earliest fragmentary remains that will come to be known as Deinosuchus, it was considered a relative of crocodiles and initially placed in the family (crocodylidae) in 1954 based on dental features. [7] However, the finding of new specimens from Texas and Georgia in 1999 led to phylogenetic analysis placing Deinosuchus in a basal position within the clade Alligatoroidea along with Leidyosuchus . [11] This classification was bolstered in 2005 by the discovery of a well-preserved Deinosuchus brain case from the Blufftown Formation of Alabama, which shows some features reminiscent of those in the modern American alligator, [12] although Deinosuchus was not considered a direct ancestor of modern alligators. [13]
The species pertaining to Deinosuchus since the resurrection of the generic name in 1979 have been traditionally recognized as D. rugosus from Appalachia and the larger D. hatcheri/riograndensis from Laramidia, characterized by differences of the shape of their osteoderms and teeth. However, based on the lack of distinctive enough differences beyond size, they have increasingly been considered all the same species. [14] [15] [16] [2] In their overview of crocodyliform material from the Kaiparowits Formation of Utah, Irmis et al. (2013) noted that D. rugosus is dubious due to its holotype teeth being undiagnostic, and recommended using Deinosuchus hatcheri for Deinosuchus material from Laramidia, while stressing that cranial Deinosuchus material from Appalachia has not been described. [16] In a 2020 study, Cossette and Brochu agreed that D. rugosus is dubious and undiagnostic, rendering it a nomen dubium , and alternatively named a new species D. schwimmeri (named after fellow paleontologist David R. Schwimmer) from Appalachia, which included several specimens previously ascribed to D. rugosus. [2] They also noted that the highly incomplete D. hatcheri holotype can be distinguished by the unique shape of the edge of its indented osteoderms, although this may not be reliable because the osteoderms of the other species may simply not be as well preserved. [2] However, due to the incomplete nature of the type species D. hatcheri, Cossette and Brochu proposed to transfer the type species to the better preserved D. riograndensis, which would allow for improved identification and differentiation of the Deinosuchus species. [2]
Phylogenetic analysis places Deinosuchus as a basal member of Alligatoroidea, as shown in the simplified cladogram below: [2]
Alligatoroidea |
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Despite its large size, the overall appearance of Deinosuchus was not considerably different from that of modern crocodilians. Deinosuchus had an alligator-like, broad snout, with a slightly bulbous tip. [9] Each premaxilla contained four teeth, with the pair nearest to the tip of the snout being significantly smaller than the other two. [14] Each maxilla (the main tooth-bearing bone in the upper jaw) contained 21 or 22 teeth. [17] The tooth count for each dentary (tooth-bearing bone in the lower jaw) was at least 22. [14] All the teeth were very thick and robust; those close to the rear of the jaws were short, rounded, and blunt. They appear to have been adapted for crushing, rather than piercing. [18] When the mouth was closed, only the fourth tooth of the lower jaw would have been visible. [14] The skull of Deinosuchus itself was of a unique shape not seen in any other living or extinct crocodilians; the skull was broad, but inflated at the front around the nares. Two holes in the premaxilla in front of the nares are present in this genus and are unique autapomorphies not seen in other crocodilians, but nothing is known at present regarding their function. [19] [20]
Modern saltwater crocodiles (Crocodylus porosus) have the strongest recorded bite of any living animal, with a maximum force of 16,414 N (1,673.8 kgf ; 3,690 lbf ) for a 4.59 meters (15.1 ft), 531 kilograms (1,171 lb) specimen. [21] The bite force of Deinosuchus has been estimated to be 18,000 N (1,835 kgf; 4,047 lbf) [9] to 102,803 N (10,483 kgf; 23,111 lbf). [21]
Deinosuchus had a secondary bony palate, which would have permitted it to breathe through its nostrils while the rest of the head remained submerged underwater. [22] The vertebrae were articulated in a procoelous manner, meaning they had a concave hollow on the front end and a convex bulge on the rear; these would have fit together to produce a ball and socket joint. [7] [23] The secondary palate and procoelous vertebrae are advanced features also found in modern eusuchian crocodilians. [22] [24]
The osteoderms (scutes) covering the back of Deinosuchus were unusually large, heavy, and deeply pitted; some were of a roughly hemispherical shape. [5] [4] Deep pits and grooves on these osteoderms served as attachment points for connective tissue. [4] Together, the osteoderms and connective tissue would have served as load-bearing reinforcement to support the massive body of Deinosuchus out of water. [17] [4] These deeply pitted osteoderms have been used to suggest that, despite its bulk, Deinosuchus could probably have walked on land much like modern-day crocodiles. [17] [22]
The large size of Deinosuchus has generally been recognized despite the fragmentary nature of the fossils assigned to it. However, estimates of how large it really was have varied considerably over the years. The original estimate from 1954 for the type specimen of the then-named "Phobosuchus riograndensis" were based on a skull of 1.5 meters (4.9 ft) and a lower jaw of 1.8 meters (5.9 ft) long, reconstructed with similar proportions to the Cuban crocodile giving a total estimated length of 15 meters (49 ft). [7] However, this reconstruction is currently considered to be inaccurate. [17] Using more complete remains, it was estimated in 1999 that the size attained by specimens of Deinosuchus varied from 8 to 10 meters (26 to 33 ft) with weights from 2.5 to 5 metric tons (2.8 to 5.5 short tons). [25] This was later corroborated when it was noted that most known specimens of D. rugosus usually had skulls of about 1 meter (3.3 ft) with estimated total lengths of 8 meters (26 ft) and weights of 2.3 metric tons (2.5 short tons). A reasonably well-preserved skull specimen discovered in Texas indicated the animal's head measured about 1.31 meters (4.3 ft), and its body length was estimated at 9.8 meters (32 ft). However, the largest fragmentary remains of D. riograndensis were 1.5 times the size of those of the average D. rugosus and it was determined that the largest individuals of this species may have been up to 12 meters (39 ft) in length and perhaps weighed as much as 8.5 metric tons (9.4 short tons). [17]
A particularly large mandibular fragment from a D. riograndensis specimen was estimated to have come from an individual with a skull length of 147.5 centimeters (4.84 ft). This length was used in conjunction with a regression equation relating skull length to total length in the American alligator to estimate a total length of 10.64 meters (34.9 ft) for this particular specimen. [26] This is only slightly lower than previous estimates for the species. Deinosuchus has often been described as the largest crocodyliform of all time. However, other crocodyliforms such as Purussaurus , Gryposuchus , Rhamphosuchus , Euthecodon , and Sarcosuchus may have equaled or exceeded it in size or length. [11]
In 1954, Edwin H. Colbert and Roland T. Bird speculated that Deinosuchus "may very well have hunted and devoured some of the dinosaurs with which it was contemporaneous". [7] Colbert restated this hypothesis more confidently in 1961: "Certainly this crocodile must have been a predator of dinosaurs; otherwise why would it have been so overwhelmingly gigantic? It hunted in the water where the giant theropods could not go." [28] [29] David R. Schwimmer proposed in 2002 that several hadrosaurid tail vertebrae found near Big Bend National Park show evidence of Deinosuchus tooth marks, strengthening the hypothesis that Deinosuchus fed on dinosaurs in at least some instances. [18] In 2003, Christopher A. Brochu agreed that Deinosuchus "probably dined on ornithopods from time to time." [30] Deinosuchus is generally thought to have employed hunting tactics similar to those of modern crocodilians, ambushing dinosaurs and other terrestrial animals at the water's edge and then submerging them until they drowned. [31] A 2014 study suggested that it would have been able to perform a "death roll", like modern crocodiles. [32]
Schwimmer and G. Dent Williams proposed in 1996 that Deinosuchus may have preyed on marine turtles. [33] Deinosuchus would probably have used the robust, flat teeth near the back of its jaws to crush the turtle shells. [18] The "side-necked" sea turtle Bothremys was especially common in the eastern habitat of Deinosuchus, and several of its shells have been found with bite marks that were most likely inflicted by the giant crocodilian. [18] [33]
Schwimmer concluded in 2002 that the feeding patterns of Deinosuchus most likely varied by geographic location; the smaller Deinosuchus specimens of eastern North America would have been opportunistic feeders in an ecological niche similar to that of the modern American alligator. They would have consumed marine turtles, large fish, and smaller dinosaurs. [17] The bigger, but less common, Deinosuchus that lived in Texas and Montana might have been more specialized hunters, capturing and eating large dinosaurs. [17] Schwimmer noted no theropod dinosaurs in Deinosuchus's eastern range approached its size, indicating the massive crocodilian could have been the region's apex predator. [18]
A 1999 study by Gregory M. Erickson and Christopher A. Brochu suggested the growth rate of Deinosuchus was comparable to that of modern crocodilians, but was maintained over a far longer time. Their estimates, based on growth rings in the dorsal osteoderms of various specimens, indicated each Deinosuchus might have taken over 35 years to reach full adult size, and the oldest individuals may have lived for more than 50 years. This was a completely different growth strategy than that of large dinosaurs, which reached adult size much more quickly and had shorter lifespans. According to Erickson, a full-grown Deinosuchus "must have seen several generations of dinosaurs come and go". [34]
Schwimmer noted in 2002 that Erickson and Brochu's assumptions about growth rates are only valid if the osteodermal rings reflect annual periods, as they do in modern crocodilians. According to Schwimmer, the growth ring patterns observed could have been affected by a variety of factors, including "migrations of their prey, wet-dry seasonal climate variations, or oceanic circulation and nutrient cycles". If the ring cycle were biannual rather than annual, this might indicate Deinosuchus grew faster than modern crocodilians, and had a similar maximum lifespan. [17]
Deinosuchus was present on both sides of the Western Interior Seaway. [10] Specimens have been described from 10 U.S. states: Utah, Montana, Wyoming, New Mexico, New Jersey, Georgia, Alabama, Mississippi, Texas, and North Carolina. [35] David Schwimmer has said Deinosuchus fossils have been found in South Carolina and Delaware as well, but none of them from those two states have been formally described. [10] A Deinosuchus osteoderm from the San Carlos Formation was also reported in 2006, so the giant crocodilian's range may have included parts of northern Mexico. [36] There is also a report describing a possible Deinosuchus scute from Colorado. [37] Deinosuchus fossils are most abundant in the Gulf Coastal Plain region of Georgia, near the Alabama border. [10] All known specimens of Deinosuchus were found in rocks dated to the Campanian stage of the Late Cretaceous period. The oldest examples of this genus lived approximately 82 Ma, and the youngest lived around 73 Ma. [38]
The distribution of Deinosuchus specimens indicates these giant crocodilians may have preferred estuarine environments. [10] In the Aguja Formation of Texas, where some of the largest specimens of Deinosuchus have been found, these massive predators probably inhabited brackish-water bays. [39] Although some specimens have also been found in marine deposits, it is not clear whether Deinosuchus ventured out into the ocean (like modern-day saltwater crocodiles); these remains might have been displaced after the animals died. [10] Deinosuchus has been described as a "conspicuous" component of a purportedly distinct biome occupying the southern half of Late Cretaceous North America. [40]
Sarcosuchus is an extinct genus of crocodyliform and distant relative of living crocodilians that lived during the Early Cretaceous, from the late Hauterivian to the early Albian, 133 to 112 million years ago of what is now Africa and South America. The genus name comes from the Greek σάρξ (sarx) meaning flesh and σοῦχος (souchus) meaning crocodile. It was one of the largest pseudosuchians, with the largest specimen of S. imperator reaching approximately 9–9.5 metres (29.5–31.2 ft) long and weighing up to 3.45–4.3 metric tons. It is known from two species; S. imperator from the early Albian Elrhaz Formation of Niger, and S. hartti from the Late Hauterivian of northeastern Brazil. Other material is known from Morocco and Tunisia and possibly Libya and Mali.
Ceratosuchus is an extinct genus of alligatorine crocodylian from latest Paleocene rocks of Colorado's Piceance Basin and earliest Eocene rocks of Wyoming's Bighorn Basin in North America, a slice of time known as the Clarkforkian North American Land Mammal Age. Like its modern relatives, Ceratosuchus was a swamp-dwelling predator. It is named for the pair of flattened, triangular bony plates that extend from the back of its head.
Boverisuchus is an extinct genus of planocraniid crocodyliforms known from the middle Eocene of Germany and western North America. It was a relatively small crocodyliform with an estimated total length of approximately 2.2–3.6 metres (7.2–11.8 ft).
Hyposaurus is a genus of extinct marine dyrosaurid crocodyliform. Fossils have been found in Paleocene aged rocks of the Iullemmeden Basin in West Africa, Campanian–Maastrichtian Shendi Formation of Sudan and Maastrichtian through Danian strata in New Jersey, Alabama and South Carolina. Isolated teeth comparable to Hyposaurus have also been found in Thanetian strata of Virginia. It was related to Dyrosaurus. The priority of the species H. rogersii has been debated, however there is no sound basis for the recognition of more than one species from North America. The other North American species are therefore considered nomina vana.
Mourasuchus is an extinct genus of giant, aberrant caiman from the Miocene of South America. Its skull has been described as duck-like, being broad, flat, and very elongate, superficially resembling Stomatosuchus from the Late Cretaceous.
Wannaganosuchus is an extinct genus of small alligatorid crocodilian. It was found in Late Paleocene-age rocks of Billings County, North Dakota, United States.
Leidyosuchus is an extinct genus of alligatoroid from the Late Cretaceous of Alberta. It was named in 1907 by Lawrence Lambe, and the type species is L. canadensis. It is known from a number of specimens from the middle Campanian age Dinosaur Park Formation. It was a medium-sized alligatoroid, with a maximum skull length greater than 40 centimeters (16 in).
Harpacochampsa is a poorly known Early Miocene crocodilian from the Bullock Creek lagerstätte of the Northern Territory, Australia. The current specimen consists of a partial skull and fragments of a long, slender snout reminiscent of that of a false gharial, demonstrating that it was a piscivore in life.
The Smoky Hill Chalk Member of the Niobrara Chalk formation is a Cretaceous conservation Lagerstätte, or fossil rich geological formation, known primarily for its exceptionally well-preserved marine reptiles. Named for the Smoky Hill River, the Smoky Hill Chalk Member is the uppermost of the two structural units of the Niobrara Chalk. It is underlain by the Fort Hays Limestone Member and overlain by the Pierre Shale. The Smoky Hill Chalk outcrops in parts of northwest Kansas, its most famous localities for fossils, and in southeastern Nebraska. Large well-known fossils excavated from the Smoky Hill Chalk include marine reptiles such as plesiosaurs, large bony fish such as Xiphactinus, mosasaurs, flying reptiles or pterosaurs, flightless marine birds such as Hesperornis, and turtles. Many of the most well-known specimens of the marine reptiles were collected by dinosaur hunter Charles H. Sternberg and his son George. The son collected a unique fossil of the giant bony fish Xiphactinus audax with the skeleton of another bony fish, Gillicus arcuatus inside the larger one. Another excellent skeleton of Xiphactinus audax was collected by Edward Drinker Cope during the late nineteenth century heyday of American paleontology and its Bone Wars.
Allognathosuchus is an extinct genus of alligatorine crocodylian with a complicated taxonomic history. It was named in 1921.
Asiatosuchus is an extinct genus of crocodyloid crocodilians that lived in Eurasia during the Paleogene. Many Paleogene crocodilians from Europe and Asia have been attributed to Asiatosuchus since the genus was named in 1940. These species have a generalized crocodilian morphology typified by flat, triangular skulls. The feature that traditionally united these species under the genus Asiatosuchus is a broad connection or symphysis between the two halves of the lower jaw. Recent studies of the evolutionary relationships of early crocodilians along with closer examinations of the morphology of fossil specimens suggest that only the first named species of Asiatosuchus, A. grangeri from the Eocene of Mongolia, belongs in the genus. Most species are now regarded as nomina dubia or "dubious names", meaning that their type specimens lack the unique anatomical features necessary to justify their classification as distinct species. Other species such as "A." germanicus and "A." depressifrons are still considered valid species, but they do not form an evolutionary grouping with A. grangeri that would warrant them being placed together in the genus Asiatosuchus.
Voay is an extinct genus of crocodile from Madagascar that lived during the Late Pleistocene to Holocene, containing only one species, V. robustus. Numerous subfossils have been found, including complete skulls, noted for their distinctive pair of horns on the posterior, as well as vertebrae and osteoderms from such places as Ambolisatra and Antsirabe. The genus is thought to have become extinct relatively recently. It has been suggested to have disappeared in the extinction event that wiped out much of the endemic megafauna on Madagascar, such as the elephant bird and Malagasy hippo, following the arrival of humans to Madagascar around 2000 years ago. Its name comes from the Malagasy word for crocodile.
Prodiplocynodon is an extinct genus of basal crocodyloid crocodylian. It is one of the only crocodyloids known from the Cretaceous and existed during the Maastrichtian stage. The only species of Prodiplocynodon is the type species P. langi from the Lance Formation of Wyoming, known only from a single holotype skull lacking the lower jaw.
Pakasuchus is a genus of notosuchian crocodyliform distinguished by its unusual mammal-like appearance, including mammal-like teeth that would have given the animal the ability to chew. It also had long, slender legs and a doglike nose. Fossils have been found in the Galula Formation of Rukwa Rift Basin of southwestern Tanzania, and were described in 2010 in the journal Nature. Pakasuchus is originally considered to lived approximately 105 million years ago, in the mid-Cretaceous, but later age of site is reconsidered to the late Cretaceous, Cenomanian to Campanian instead. The type species is P. kapilimai. Pakasuchus means "cat crocodile" in reference to its catlike skull.
During most of the Late Cretaceous the eastern half of North America formed Appalachia, an island land mass separated from Laramidia to the west by the Western Interior Seaway. This seaway had split North America into two massive landmasses due to a multitude of factors such as tectonism and sea-level fluctuations for nearly 40 million years. The seaway eventually expanded, divided across the Dakotas, and by the end of the Cretaceous, it retreated towards the Gulf of Mexico and the Hudson Bay. This left the island masses joined in the continent of North America as the Rocky Mountains rose. From the Cenomanian to the end of the Campanian ages of the Late Cretaceous, Appalachia was separated from the rest of North America. As the Western Interior Seaway retreated in the Maastrichtian, Laramidia and Appalachia eventually connected. Because of this, its fauna was isolated, and developed very differently from the tyrannosaur, ceratopsian, hadrosaurid, pachycephalosaur and ankylosaurid dominated fauna of the western part of North America, known as "Laramidia".
Thecachampsa is an extinct genus of gavialoid crocodylian, traditionally regarded as a member of the subfamily Tomistominae. Fossils have been found from the eastern United States in deposits of Miocene age. Those named in the 19th century were distinguished primarily by the shape of their teeth, and have since been combined with T. antiquus. More recently erected species were reassigned from other genera, although their assignment to Thecachampsa has since been questioned.
Teratophoneus is a genus of tyrannosaurine theropod dinosaur that lived during the late Campanian age of the Late Cretaceous period, in what is now Utah. It contains a single known species, T. curriei. It is known from an incomplete skull and postcranial skeleton recovered from the Kaiparowits Formation and was specifically named T. curriei in honor of famed paleontologist Philip J. Currie.
Brevirostres is a paraphyletic group of crocodilians that included alligatoroids and crocodyloids. Brevirostres are crocodilians with small snouts, and are distinguished from the long-snouted gharials. It is defined phylogenetically as the last common ancestor of Alligator mississippiensis and Crocodylus niloticus and all of its descendants. This classification was based on morphological studies primarily focused on analyzing skeletal traits of living and extinct fossil species, and placed the gharials outside the group due to their unique skull structure, and can be shown in the simplified cladogram below:
Planocraniidae is an extinct family of eusuchian crocodyliforms known from the Paleogene of Asia, Europe and North America. The family was coined by Li in 1976, and contains three genera, Boverisuchus, Duerosuchus and Planocrania. Planocraniids were highly specialized crocodyliforms that were adapted to living on land. They had extensive body armor, long legs, and blunt claws resembling hooves, and are sometimes informally called "hoofed crocodiles".
Furcatoceratops is a genus of centrosaurine ceratopsid dinosaur from the Late Cretaceous Judith River Formation of Montana. The type species is Furcatoceratops elucidans.