Astreptorhachis fossil map
Where fossils of Astreptorhachis have been found, shown on the Earth as it looked about 300 million years ago and on today’s map.
Dots are fossil collections recorded in the Paleobiology Database. The “then” view moves today’s fossil sites back to their positions 300 million years ago (the time slice nearest the median age of the fossils) using the Merdith et al. (2021) plate model; positions are approximate. Open on the timeline map →
| Group | Early tetrapods & amphibians |
|---|---|
| Lived | 303.7–298.9 million years ago (Gzhelian) |
| Periods | Carboniferous |
| Family | Dissorophidae |
| Named by | Vaughn 1971 |
| Fossil records | 1 occurrences at 1 locations (PBDB) |
| Found in | United States |
| Rock formations | txn:37017 |
About Astreptorhachis
Astreptorhachis is an extinct genus of Late Carboniferous dissorophid temnospondyl. It is known only from one species, Astreptorhachis ohioensis, that was collected from the Casselman Formation in Jefferson County, Ohio by the Ohio Geological Survey in 1953 and described by Peter Vaughn in 1971. The holotype and only known specimen consists of a few neural spines and is currently reposited in the Smithsonian Museum of Natural History. The genus name derives from the Greek words astreptos ("inflexible") and rhachis ("backbone"). The specimen was recognized as being similar to the dissorophid Platyhystrix rugosa from the southwestern United States in having greatly elongate neural spines,although subsequent work on P. rugosa has revealed that the spine is not particularly elongate, instead being capped by an elongate osteoderm. Astreptorhachis is differentiated from Platyhystrix by the fusion of successive neural spines and the extensively developed tubercles that cover the external surfaces. It is speculated that the elongation of the spines served to stiffen the backbone, being advantageous for terrestrial locomotion, but the purpose of the fusion of successive spines remained unclear in the absence of other material of this taxon.
Text in “About” is quoted from the Wikipedia article Astreptorhachis (revision 1378518540), licensed under CC BY-SA 4.0; introduction excerpted verbatim, formatting removed. Ages, family, authority and fossil records: Paleobiology Database, accessed 23 October 2026. Ages are those of the rock layers the fossils were found in. Wikidata: Q4811401.
