Pronunciation: Both-ree-oh-lee-pis young-ee Translation: "Yeung's pitted scale" - named after Monica Yeung of Canberra, who helped to organise the preparation of the Canowindra fossils, and the pitted ornamentation of the bony plates. Period: Late Devonian (360 million years ago)
Description - small mud-eating armoured fish
Class - Placodermi ('plated-skin' - the armoured fishes) Order - Antiarchi (armoured pectoral fins) Family - Bothriolepidae ('the family of Bothriolepis') Genus - Bothriolepis Species - Bothriolepis yeungae
Length - 50 cm
Bothriolepis was the most successful of all the placoderms. There are more than 100 different species known, and the genus is found on every continent. It seems to have spent most of its life in fresh-water rivers and lakes, as most fossils are found in fresh-water sediments, but must have been able to tolerate salt-water as well - how else could they have spread so widely? Bothriolepis yeungae is the species found at Canowindra, and more than 1500 specimens have been counted so far - it was a very common fish in Canowindra's ancient lake. The structure of the mouth suggests that Bothriolepis fed on algae and other micro-organisms living on the bottom surface of the lake. The long, stiff fins may have provided enough hydro-dynamic lift for the animal to 'take-off' from the lake-bottom and regularly swim in mid water. The heavy bony armour would probably have caused Bothriolepis to start to sink as soon as it stopped swimming, but provided good protection from the lake's predatory fish. Superficially, small placoderms like Bothriolepis resemble some of the modern 'armoured' cat-fishes from South America. These bottom-dwelling catfish live on nutrient rich muds and algae, but the resemblance is indeed superficial. Placoderms are completely extinct, whilst catfishes are specialised bony fishes. The resemblance is probably the result of a similarity in ecology and life-style.
