Lyrarapax

Extinct genus of Amplectobeluid radiodont

Lyrarapax is a radiodont genus of the family Amplectobeluidae that lived in the early Cambrian period 520 million years ago. Its neural tissue indicates that the radiodont frontal appendage is protocerebral, resolving parts of the arthropod head problem and showing that the frontal appendage is homologous to the antennae of Onychophorans and labrum of euarthropods. Its fossilized remains were found in Yunnan in southwestern China. A second species was described in 2016, differing principally in the morphology of its frontal appendages. It is a small animal, with L. unguispinus and L. trilobus measuring up to 8.3 cm (3.3 in) and 3.9 cm (1.5 in) in body length respectively.

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