A recent discovery in south-west Kyrgyzstan is shedding light on the lifestyle of this unusual shark. Reporting in the most recent issue of the Journal of Vertebrate Palaeontology, a team of German scientists have discovered a fossil site which they believe was the shark nursery for Palaeoxyris alterna. A shark nursery is a large, shallow and safe area of water where young sharks are raised in large groups by adult members of the species.
|The fossils and a computer reconstruction of the egg cases of Palaeoxyris alterna|
Fossil sharks are generally rather rare. This is partly due to their cartilaginous skeleton, which usually is not preserved as a fossil. Consequently, painstaking searches of large quantities of rock often yield very little reward. As Michael Buchwitz, an author of the report, noted, 'The fossil record of sharks is no laughing matter; a spine here, a tooth there, or three miniscule denticles (small spines of the skin) picked from a 10 kilogram sample. Therefore, dozens of egg capsules alongside juvenile teeth in one deposit is a dream come true!'