Article: A tiny microsaur from the Lower Permian of Texas: size constraints in Palaeozoic tetrapods

Quasicaecilia texana gen. et sp. nov., from the Lower Permian of Texas, is a very small microsaur in which the nasal bones form the front margin of the skull and the cultriform process of the parasphenoid is not in contact with the sphenethmoid. The bones of the otic-occipital region are fused to one another, and the otic capsule and stapes are very large relative to other cranial dimensions, giving a superficial resemblance to modern caecilians. Many of the unusual cranial features of this species may be attributed to its small size. The relatively large size of the sensory capsules in Palaeozoic amphibians with an adult skull length less than about 2 cm results in significant modification of the area of the otic capsule and jaw articulation.