Eryops megacephalus

Overview

Eryops megacephalus was a large temnospondyl with a broad head and robust limbs, studied as an amphibian relative of the Early Permian. Many features can be examined, from the front of its broad mouth to small wrist and ankle bones.^[3][1]

Key facts

An old interpretation of an extra small thumb was revised. A 2015 reassessment confirmed that Eryops had four fingers on its forefeet. Even a familiar body region can appear different when its bones are compared again.^[1]

Time and place

It is associated with Early Permian material from around 290–280 million years ago. Museum specimens are recorded from the Belle Plains Formation in present-day Texas, United States. This was a time when early terrestrial vertebrates developed diverse bodies.^[2]

The time range describes source context, not the complete duration of this species.

Size, form and skeleton

A broad snout, robustly ossified limbs, and well-developed muscle attachment sites are characteristic. Four fingers have been studied on the forefeet. Research using a body model of the genus Eryops about 1.8 m long estimated a body mass of about 160 kg.^[3][1][4]

Habitat and reproduction

The large head and robust limbs provide evidence for studying how its body was supported. Muscle attachment sites are compared alongside wrists and ankles. Questions about how this ancient amphibian relative used land and water begin in several body regions.^[3][1]

Fossil discovery

The Smithsonian’s USNM V6721 is registered as a mounted skeleton combining several sources of material. Other researchers have closely compared limb, wrist, and ankle bones. Museum displays and renewed study of small bones together reveal this animal’s appearance.^[2][3][1]

References

1. Dilkes2015 — Wrists and ankles of temnospondyls
2. Smithsonian — Skeletal record of Eryops megacephalus
3. Pawley & Warren2006 — The limb skeleton of Eryops
4. Approximate size comparison — Genus guide and reconstruction of Eryops
5. Smithsonian — Skeletal record of Eryops megacephalus
6. Pawley & Warren2006 — The limb skeleton of Eryops
7. Dilkes2015 — Wrists and ankles of temnospondyls
8. Brink & Reisz2014 — Tooth diversity in Dimetrodon
9. American Museum of Natural History — A Dimetrodon skeleton
10. Harvard Museum — Dimetrodon

Research questions

How did the limbs support a broad, heavy front body? Researchers compare bone proportions, muscle attachment sites, and three-dimensional body models. Small features such as finger number can be studied alongside whole-body properties such as mass.^[3][4][1]

Observation

Move your gaze from the broad head to the shoulders, forelimbs, and four fingers. Also examine the robust structures of the rear body and limbs.^[3][1]