Tiktaalik

Tiktaalik roseae, replica of the holotype

• North America ( Ellesmere Island, Nunavut Territory, Canada )

• Tiktaalik roseae

Tiktaalik ( Inuktitut for " burbot ", a large freshwater and brackish water fish) was a genus of amphibians similar meat -finned fishes ( Sarcopterygii ), whose fossils were found in sedimentary rocks of the Upper Devonian of Ellesmere Island ( Ellesmere Iceland ) in northern Canada. So far, only the type Tiktaalik is roseae known.

As a mosaic form Tiktaalik is a testament to the order in which bonefish characteristics of land vertebrates ( tetrapods ) developed, even before the first Uramphibien as Acanthostega and Ichthyostega arise from them. As ancestors of Tiktaalik have Neil Shubin and Others (2006) Panderichthys -like fish from.

Features

Tiktaalik is similar to other Fleischflossern as the coelacanth and the lungfish in scalation, in the construction of fins, lower jaw and palate. Amphibian -like are the shortened skull roof and the ear region, the movable neck and forelimbs: Equipped with elbow and wrist to remind the pectoral fin of Tiktaalik to the poor, but they ended up in fin rays, not in the fingers. Pelvic girdle and hind limbs show a mosaic of primitive and derived features. The pelvic bones of Tiktaalik are big and strong compared with those of other beflosster Tetrapodomorphen. However, they are neither associated with the sacral ribs is still an ischium present. The flat, elongated snout of up to 20 cm long skull gives the animal a crocodile -like appearance. A detailed analysis of the skull showed that Tiktaalik roseae " is morphologically intermediate between the conditions in primitive fish and those that we know of tetrapods. " ( Downs et al., 2008)

According to Daeschler u a and Shubin and a Tiktaalik was a resident of the shallow coastal water; his remains were found in the deposits of a river delta. The pectoral fins, he used to travel on the river bottom. He could be supported, among others, while stretching the shoulder and elbow as on front legs from the ground.

Skull from the front

Forelimb ( front) with shoulder belt (rear)

Shoulder girdle and forelimb

Naming

The discoverers of the fossils on Ellesmere Iceland, Farish A. Jenkins Jr., Neil Shubin and Ted Daeschler, would carry the locality and the resident Inuit, who had issued the excavation permit, invoice for the award of the scientific name. You made a request with the request for name suggestions to the elders of Nunavut, the Inuit Qaujimajatuqangit Katimajiit. From the two proposals, " Siksagiaq " and " Tiktaalik ", chose the latter paleontologists from which in Inuktitut means as much as " burbot " or " large freshwater fish ".