(San Angelo lizard).
Named By: E. C. Olsen & J. R. Beerbower - 1953.
Classification: Chordata, Synapsida, Pelycosauria, Caseidae.
Species: A. dolani (type), A. greeni, A. romeri.
Size: A. dolani 3 - 3.5 meters long. A. greeni 4 meters long. A. romeri 2.5 meters long.
Known locations: USA, Oklahoma & Texas.
Time period: Kungurian to Wordian of the Permian.
Fossil representation: Remains of several partially preserved individuals.
heavily built pelycosaur
similar to Cotylorhynchus,
shared its habitat with Caseopsis and Caseoides,
typified by the type genus of the group, Casea.
These were a
distinctive group of pelycosaurs that don’t seem to have been that
specially adapted beyond being quadrupedal and having large round
bodies that are often described as being barrel-like. Herbivores like
these seem to have been quite common at this time, and were likely
one of the principal prey types of predatory pelycosaurs like the sail
Angelosaurus species came in a range of sizes with A. greeni being the largest at four meters and A. romeri the smallest at 2.5 meters. The type species A. dolani is roughly intermediate between these two in terms of size. The oldest species of Angelosaurus are A. dolani and A. greeni (Kungurian-Roadian), while A. romeri seems to have existed slightly later in the Permian (Roadian-Wordian). This may indicate that as time went on the Angelosaurus genus evolved to become physically smaller.
- The San Angelo Formation, Permian of Texas, and its Vertebrates, E. C. Olsen & J. R. Beerbower - 1953.
- Permian vertebrates from Oklahoma and Texas. Part I.—Vertebrates from the Flowerpot Formation, Permian of Oklahoma, E. C. Olsen & H. Barghusen - 1962.