Thrinaxodon liorhinus

Overview

Thrinaxodon liorhinus is an animal studied through head growth, hands and feet, and skeletons inside burrows. Different clues are known, ranging from small skulls to limb ends and the places where fossils were preserved. It can be explored from several perspectives.^[1][2][3]

Key facts

Both the forefeet and hind feet are described as having five digits. The arrangement of small bones within the digits has also been studied. Bone structure can be compared beyond the externally visible tips of the feet.^[2]

Time and place

Skeletons from Early Triassic burrows in present-day South Africa have been studied. The Triassic as a whole spans roughly 250–200 million years ago. Preservation within a burrow adds questions different from those raised by body form.^[3][4]

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

Size, form and skeleton

Research on the hands and feet describes the five digits of the forefeet and hind feet and the arrangement of bones within them. Research on head growth compares skull measurements across specimens. Small structures at the limb ends and the growing head represent features at different scales.^[1][2]

Habitat and reproduction

What clues to life might a skeleton inside a burrow provide? In 2013, researchers proposed an interpretation involving dormancy based on the fossil's occurrence. This is an example of exploring possible ways of life through the place where an organism was preserved.^[3]

Fossil discovery

After a 1995 study of hand and foot evolution, a skeleton inside a burrow was studied in 2013. Head growth and shape were compared in 2015. Limbs, heads, and places of preservation lead to different questions.^[1][2][3]

References

1. Ontogeny of the Early Triassic Cynodont Thrinaxodon liorhinus: Cranial Morphology
2. Hopson (1995) — Evolution of hands and feet in mammal relatives
3. Fernandez et al. (2013) — Early Triassic skeletons found in a burrow
4. International Commission on Stratigraphy (2024) — Geological time chart
5. Natural History Museum, London — Cynognathus and synapsid collection material
6. Benoit·Buffa·Day (2026) — The maxillary canal of Cynognathus

Research questions

How do head size and shape change during growth? Researchers compared skulls from several specimens and compiled measurements by region. This research examines differences between growth stages rather than a single outline.^[1]

Observation

Move your gaze from the head to the forefeet and hind feet. Picturing the five digits and the small bones within them helps compare the overall body with the structure of the limb ends.^[1][2]