Protanguilla

Protoanguilla palau is a species that is at the basis of the current and next eel-like features today's eels and those which are otherwise found in only Cretaceous species or even earlier. Therefore deemed to be a living fossil. The species was discovered in an underwater cave in front of Palau in 2009.

Features

Protanguilla palau is elongated, with cylindrical front fuselage, which is moderately flattened behind and goes into a very flat tail. The previously examined animals were about four and a half to twenty inches long. The snout is flattened. Opening the gill is an oval tube with a short collar fringed. The scales are small and oval. They cover the body in a basket weave -like pattern, but missing around the eyes, the mouth and the tip of the snout. The lateral line runs through 80 to 84 scales. The pectoral fins set at the lower third of the body and have 18 or 19 branched rays. Pelvic fins absent, as with all recent eel-like. The dorsal and anal fins extend over more than two thirds of the body length and are fused with the caudal fin. The dorsal fin has 176-189, anal fin 175-191 unbranched rays on the caudal fin ten.

Protanguilla palau has a number of features that are consistent with either today or eel-like with Cretaceous representatives or completely unique. In contrast to all other eel-like today, but just as some Cretaceous representatives of the order, Protanguilla palau has a Zwischenkieferbein and a Metapterygoid, and neither symplectic and Os quadratum nor the upper Hypuralia are fused. As with today's eel-like, but in contrast to the Cretaceous representatives, the back, tail and anal fins are fused palau even at Protoanguilla and a Entopterygoid missing. Features which are still more original than that of all known modern or fossil eel-like, are the presence of a gill Reuse and less than 90 vertebrae.

Occurrence

Protanguilla palau has only been out of an underwater cave in Palau in 35 meters depth known.

Systematic position

Due to the unique combination of features Protanguilla was provided palau in a separate genus and family within the eel-like. Anatomical and molecular comparisons suggest that the type faces as a sister group to all other present and eel-like parted from it before about 220 million years ago during the transition from Triassic to Jurassic.