Temporal range: Late Carboniferous, 300 Ma
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Araeoscelidia
Genus: Spinoaequalis
deBraga & Reisz, 1995
  • S. schultzei deBraga & Reisz, 1995 (type)

Spinoaequalis is an extinct genus of diapsid reptile.

The 30 cm (1 ft) long creature, known from fossils found in Kansas, United States, was one of the first diapsids, along with Petrolacosaurus. It was also the first reptile to return to the water, evolving shortly after Hylonomus, the oldest confirmed reptile. Spinoaequalis was not fully aquatic, frequently returning to dry land. It probably swam using its laterally flattened, fanned tail. Its name means "symmetrical spine" referring to its deep, laterally compressed tail. Spinoaequalis has been found along with beautifully preserved marine fish, suggesting it occasionally left fresh water streams for the sea.

Spinoaequalis was described and named by Michael deBraga and Robert Reisz in 1995.

This page was last updated at 2023-12-05 12:00 UTC. Update now. View original page.

All our content comes from Wikipedia and under the Creative Commons Attribution-ShareAlike License.


If mathematical, chemical, physical and other formulas are not displayed correctly on this page, please useFirefox or Safari