Cotylorhynchus
A large herbivorous caseid synapsid from the Permian of North America.
Cotylorhynchus is an extinct genus of herbivorous caseid synapsids that lived during the late Lower Permian (Kungurian) and possibly the early Middle Permian (Roadian) in what is now Texas and Oklahoma, United States. The large number of specimens found makes it the best-known caseid. The genus is represented by three species, the largest of which could reach more than 6 meters (20 feet) in length.
- Time period
- Late Lower Permian (Kungurian) to possibly early Middle Permian (Roadian)
- Location
- Texas and Oklahoma, United States
- Diet
- Herbivorous
- Known for
- Best-known caseid; massive barrel-shaped body; very small head compared to body size
- Maximum length
- More than 6 meters (20 feet)
- Number of species
- Three (C. romeri, C. hancocki, C. bransoni)
Lore & Background
The genus name Cotylorhynchus comes from the Greek kotyle ('cup' or 'hollow') and rhynchos ('beak' or 'snout'), named after the cup-shaped bony surface surrounding the nasal opening. Numerous specimens were later discovered in about 20 sites near Norman, Oklahoma, totaling around 40 individuals. The species C. romeri honors paleontologist Alfred Sherwood Romer. Cotylorhynchus had a short, forward-sloping snout, very large external nares, and a skull roof with numerous small depressions. The body was massive and barrel-shaped, ending with a long tail, and the limbs were short and robust with broad hands and feet bearing powerful claws. The barrel-shaped body likely housed large intestines, suggesting the animal fed on large quantities of low-nutrition plants. The teeth were tricuspid (except the most anterior), and numerous palatal teeth were present. The vertebral column included 25 or 26 presacral vertebrae, three sacral vertebrae, and about 55 caudal vertebrae.
Reader's Guide
Cotylorhynchus is significant as the best-known caseid, providing key insights into the anatomy and ecology of large herbivorous synapsids from the Permian. Its massive, barrel-shaped body and small head are characteristic of caseids, and the large number of specimens has allowed detailed study of its skeletal structure, including the skull, teeth, and postcranial skeleton. The species C. romeri shows possible sexual dimorphism in size, and its teeth indicate adaptations for processing tough plant material. The discovery of numerous specimens in a relatively thin stratigraphic interval in Oklahoma has made Cotylorhynchus a valuable index fossil for the Hennessey Formation. Its legacy lies in its role as a representative of early herbivorous synapsids and as a case study in Permian vertebrate paleontology.
Did You Know?
- The genus name Cotylorhynchus means 'cup snout,' referring to the cup-shaped bony surface around the nasal opening.
- The largest species of Cotylorhynchus could reach more than 6 meters (20 feet) in length.
- The type species C. romeri was named after paleontologist Alfred Sherwood Romer.
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