Lepospondyli (class Amphibia) A group of small, Palaeozoic amphibians in which the vertebrae have spool-shaped centra (see CENTRUM) below the neural arches. The centra were each perforated lengthwise, providing a channel for the notochord. The lepospondylous, or ‘husk’, vertebra also occurs in living amphibians, but its evolutionary derivation is unclear.

Lepospondyli Group of small Palaeozoic amphibians, distinguished by the possession of vertebrae with spool- shaped centra below the neural arches. Each centrum (the massive part of the vertebra) was perforated lengthwise, providing a channel for the notochord. The lepospondylous, or ‘husk’, vertebra also occurs in living amphibians, but its evolutionary derivation is unclear.

Microsauria A group of very small, Carboniferous and Permian amphibians that are thought to be ancestral to the modern Apoda.