Deinosuchus rugosus

(Phobosuchus riograndensis)

(DI-no-SOUK-us ru-GO-sus)

Period: Late Cretaceous, Aguja Formation

Location: Big Bend National Park, Texas

Collection: Texas Memorial Museum at Austin

Collected by: ?

Size: ?

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Description: Deinosuchus means “terrible crocodile” and is one of the largest crocodilian that ever lived.    They reached lengths of 40 feet, a skull of 6 feet, and weighed 12,000 pounds.  Their bodies were covered in plate-like scales called osteoderm.  Deinosuchus has an estimated lifespan of 50 years, longer than any crocodilian alive today.  Unlike modern crocodiles and dinosaurs, Deinosuchus did not have a growth rate like other reptiles.  It would mature in 10 years but would have continued to grow like a juvenile for 30-40 years.  Only in advanced age would the animal stop growing larger.

See the Chasmosaurus mariscalensis vertebra covered in bite marks.

Like today’s crocodiles, Deinosuchus had a semi-upright gate, meaning their legs are not quite sprawled and they can actually gallop on land.  Crocodilians that came before Deinosuchus had a fully erect gate, meaning their legs were held under their body all the time.  They also lived inland not in rivers, some were even bipedal.  Thus the sprawled stance of the crocodilian is related to their living conditions not a basil characteristic.

Big Bend National Park was once a lush warm land near a shallow inland ocean, think Louisiana.  Large rivers crossed the forests giving Deinosuchus a perfect location to live.

Crocodilian teeth are hollow with a new tooth growing inside.  Teeth are constantly being replaced and young crocs having larger replacements monthly.

Alligators generally have a wider muzzle than crocodiles.