Deinosuchus: Difference between revisions

{{short description|Genus of a giant crocodylian}}

{{featured article}}

{{Use American English|date=September 2020}}

{{Automatic taxobox

| image = Deinosuchus hatcheri - Natural History Museum of Utah - DSC07251.JPG

| image_caption = Reconstructed ''D. hatcheri'' skeleton at the [[Natural History Museum of Utah]]

| taxon = Deinosuchus

| authority = [[William Jacob Holland|Holland]], 1909

| type_species_authority = Holland, 1909

| subdivision_ranks = Other [[species]]

| synonyms = *''Polydectes'' <small>[[Edward Drinker Cope|Cope]], 1869</small>

*''Phobosuchus'' <small>[[Franz Nopcsa von Felső-Szilvás|Nopcsa]], 1924</small>

'''''Deinosuchus''''' ({{IPAc-en|ˌ|d|aɪ|n|ə|ˈ|sj|uː|k|ə|s}}) is an [[extinct]] [[genus]] of [[Alligatoroidea|alligatoroid]] [[crocodilian]], related to modern [[alligator|alligators]] and [[Caiman|caimans]], that lived 82 to 73&nbsp;million years ago (Ma), during the late [[Cretaceous]] [[Geologic time scale#Terminology|period]]. The name translates as "terrible crocodile" and is derived from the [[Ancient Greek|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 [[Skull|cranial]] material found in recent years has expanded scientific understanding of this massive predator.

 

 

''Deinosuchus'' fossils have been described from 10 [[U.S. state]]s, including Texas, Montana, and many along the [[East Coast of the United States|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 [[dinosaur]]s. It may have also fed upon [[sea turtle]]s, fish, and other aquatic and terrestrial prey.

 

==Description==

{{multiple image |align=left |direction=vertical |width=269x269px

|image1=Deinosuchus illustration Andrey Atuchin.jpg |caption1=Life restoration of ''D. rugosus''

}}

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.<ref name="schwimmer-lifetimes">{{cite book |title=King of the Crocodylians: The Paleobiology of Deinosuchus |last=Schwimmer |first=David R. |publisher=[[Indiana University Press]] |pages=1–16 |chapter=The Life and Times of a Giant Crocodylian

|year=2002 |url=https://books.google.com/books?id=0OsPJnC4CCwC |isbn=978-0-253-34087-0}}</ref> Each [[premaxilla]] contained four teeth, with the pair nearest to the tip of the snout being significantly smaller than the other two.<ref name="schwimmer-species">{{cite book |title=King of the Crocodylians: The Paleobiology of Deinosuchus |last=Schwimmer |first=David R. |publisher=[[Indiana University Press]] |pages=107–135 |chapter=How Many ''Deinosuchus'' Species Existed? |year=2002 |isbn=978-0-253-34087-0}}</ref> Each [[maxilla]] (the main tooth-bearing bone in the upper jaw) contained 21 or 22&nbsp;teeth.<ref name="schwimmer-size">{{cite book |title=King of the Crocodylians: The Paleobiology of Deinosuchus |last=Schwimmer |first=David R. |publisher=[[Indiana University Press]] |pages=42–63 |chapter=The Size of ''Deinosuchus'' |year=2002 |url=https://books.google.com/books?id=0OsPJnC4CCwC |isbn=978-0-253-34087-0}}</ref> The tooth count for each [[dentary]] (tooth-bearing bone in the lower jaw) was at least 22.<ref name="schwimmer-species"/> All the teeth were very thick and robust; those close to the rear of the [[jaw]]s were short, rounded, and blunt. They appear to have been adapted for crushing, rather than piercing.<ref name="schwimmer-prey">{{cite book |title=King of the Crocodylians: The Paleobiology of Deinosuchus |last=Schwimmer |first=David R. |publisher=[[Indiana University Press]] |pages=167–192 |chapter=The Prey of Giants |year=2002 |url=https://books.google.com/books?id=0OsPJnC4CCwC |isbn=978-0-253-34087-0}}</ref> When the mouth was closed, only the fourth tooth of the lower jaw would have been visible.<ref name="schwimmer-species"/> 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.<ref>[https://phys.org/news/2020-08-power-deinosuchus-teeth-size-bananas.html Teeth]</ref><ref>[https://www.tandfonline.com/doi/full/10.1080/02724634.2020.1767638?scroll=top&needAccess=true Tandfonline]</ref>

 

 

 

The [[osteoderm]]s (scutes) covering the back of ''Deinosuchus'' were unusually large, heavy, and deeply pitted; some were of a roughly hemispherical shape.<ref name="holland">{{cite journal |title=''Deinosuchus hatcheri'', a new genus and species of crocodile from the Judith River beds of Montana |last=Holland |first=W.J. |journal=Annals of the Carnegie Museum |volume=6 |year=1909 |pages=281–294|doi=10.5962/p.214851 |s2cid=91672986 |doi-access=free }}</ref><ref name="schwimmer-early">{{cite book |title=King of the Crocodylians: The Paleobiology of Deinosuchus |last=Schwimmer |first=David R. |publisher=[[Indiana University Press]] |pages=17–41 |chapter=The Early Paleontology of''Deinosuchus'' |year=2002 |isbn=978-0-253-34087-0}}</ref> Deep pits and grooves on these osteoderms served as attachment points for connective tissue.<ref name="schwimmer-early"/> Together, the osteoderms and connective tissue would have served as load-bearing reinforcement to support the massive body of ''Deinosuchus'' out of water.<ref name="schwimmer-size"/><ref name="schwimmer-early"/> 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.<ref name="schwimmer-size"/><ref name="cloudsley-thompson"/>

|title=How the 'terror crocodile' grew so big|author1=Erickson, Gregory M. |author2=Brochu, Christopher A. |journal=[[Nature (journal)|Nature]]|volume=398|date=March 1999|pages=205–206|doi=10.1038/18343|issue=6724|bibcode=1999Natur.398..205E |s2cid=4402210 |url=http://doc.rero.ch/record/14903/files/PAL_E2045.pdf }}</ref> This was later corroborated when it was noted that most known specimens of ''D. rugosus'' usually had skulls of about {{Convert|1|m|sigfig=2|sp=us|ft}} with estimated total lengths of {{Convert|8|m|sp=us}} and weights of {{convert|2.3|MT|ST}}. A reasonably well-preserved skull specimen discovered in [[Texas]] indicated the animal's head measured about {{Convert|1.31|m|sp=us|ft}}, and its body length was estimated at {{Convert|9.8|m|sp=us}}. 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 {{Convert|12|m|sp=us}} in length and perhaps weighed as much as {{convert|8.5|MT|ST}}.<ref name="schwimmer-size"/>

 

 

==Paleobiology==

===Diet===

[[File:Kritosaurus BW.jpg|thumb|''Deinosuchus'' may have preyed upon large [[ornithopod]]s. ''[[Kritosaurus]]'' lived alongside the giant crocodilian in the [[Aguja Formation]] ecosystem.<ref name="sankey">{{cite journal

|s2cid=131590548

|url=http://geology.csustan.edu/julia/pdf/sankey-2001.pdf

|url-status=dead

|archive-url=https://web.archive.org/web/20110719181856/http://geology.csustan.edu/julia/pdf/sankey-2001.pdf

}}</ref>]]

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".<ref name="colbert-bird"/> 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."<ref name="colbert-dinoworld">{{cite book

|isbn=978-0-632-04501-3

|page=263

[[File:Cráneo de Deinosuchus Riograndensis.jpg|thumb|left|Reconstructed skull of ''D. riograndensis'', Museo de la Evolución de Puebla]]

Schwimmer and G. Dent Williams proposed in 1996 that ''Deinosuchus'' may have preyed on [[Sea turtle|marine turtles]].<ref name="schwimmer-williams">{{cite journal

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 [[Dorsum (biology)|dorsal]] osteoderms of various specimens, indicated each ''Deinosuchus'' might have taken over 35&nbsp;years to reach full adult size, and the oldest individuals may have lived for more than 50&nbsp;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".<ref name="connor">{{cite news |title=Solved: Mystery of crocodile that feasted on dinosaurs |work=[[The Independent]] |publisher=[[Independent News & Media]] |date=March 18, 1999 |last=Connor |first=Steve}}</ref>

 

 

 

 

==See also==

 

{{clear}}

 

== References ==

{{reflist|25em}}

 

 

{{Extinct Crocodilia|A.}}

{{Taxonbar|from=Q133223|from2=Q19078819}}

 

[[Category:Apex predators]]

[[Category:Late Cretaceous crocodylomorphs of North America]]

[[Category:Campanian genus extinctions]]

[[Category:Prehistoric pseudosuchian genera]]