Rebellatrix

Rebellatrix (No. 4, bottom right) (1) Wantzosaurus ( Trematosauria ), (3 ) Saurichthys, (5) Hovasaurus.

• Sulphur Mountain Formation ( British Columbia, Canada)

Rebellatrix is a genus of fish bones from the order of the coelacanth. The only kind described so far is Rebellatrix divaricerca. Fossils of the species were found in the Wapiti Lake Provincial Park in British Columbia in the Canadian Rocky Mountains and dated to the Early Triassic. The holotype is an almost completely preserved, 54 cm long sample in which only parts of the head and paired fins are missing. The paratypes are incomplete. Two ( 25.5 69 cm long) consist of a rear half of the body, a third of an isolated tail fin.

The caudal fin is forked at Rebellatrix and thus unique among coelacanths. This against " normal" Quastenflosseranatomie " rebellious " feature was for the authors of the first description of the reason for the choice of the name Rebellatrix. The Style epithet divaricerca is composed of the Latin verb "diva rico" ( = spread apart ) together and the Greek " kerkos " ( = tail).

Features

Rebellatrix was a slender coelacanth, which could reach an estimated length of 1.30 m. The most striking feature of the genus is the bifurcated completely symmetrical tail fin with expiring two ends in tips. The tail fins stem was flattened laterally. The segmentation of the distal portions of the tail fin rays was reduced. At the top and bottom of the tail fin, the fin rays were reinforced. Overall, the tail fin has been mainly supported by thick, unsegmented fin rays. The shortest tail fin ray had one-eighth the length of the longest. The mean, tassel -shaped and eponymous for coelacanth lobe of the caudal fin was reduced. The anal fin is located behind the second dorsal fin. The reaching into the tail section of the notochord is four times thinner than the part which is in the hull.

Way of life

The slender, provided with a forked tail fin body leaves a fast swimming fish suspect. Rebellatrix so that is the only coelacanth with an active lifestyle. The fossil site was found in the Rebellatrix consists of deposits of a continental shelf, this could indicate that Rebellatrix was a resident of the open ocean.

System

Within the coelacanth Rebellatrix is classified as a sister group of the suborder Latimerioidei that includes the extinct genera, inhabiting freshwaters and the marine Mawsoniidae Latimeriidae, which also includes the two still existing Quastenflosserarten.