Petropedetes natator

Odontobatrachus natator ( Syn: Petropedetes natator ) is a species of anurans from West Africa. It was described by the herpetologists George Albert Boulenger already in 1905, in 2014, however, were established due to their extraordinary features and due to molecular genetic studies, a monotypic genus and a separate family for them. The genus name comes from the Greek Odontobatrachus ( όδούς, Odous = tooth and βατραχοσ, batrachos = frog) and refers to the exceptionally long maxillary teeth and the large teeth at the tip of the lower jaw in these frogs. Currently Odontobatrachus natator is the only species within this family.

Features

The type specimen, which was present the discoverer and describer Boulenger, had a head-body length of 55 millimeters. On the back of the skin is densely granulated and provided with strips or elongated warts. The color is brown on the upper side, mostly covered with dark, black dots and bright olive-green to yellowish harnesses. The limbs are well banded. The belly is pale, white to yellowish. The eardrum is inconspicuous, its diameter is only half as large as that of the eye.

Between the toes and fingers are large webbed. The fingers are slightly elongated, flat, with enlarged, heart -shaped adhesive discs. The first finger is shorter than the second. The length of the feet reached this kind of two -fifths of the head-body length. The males have paired internal vocal sacs and oval glands on the undersides of the legs.

Particularly striking is the dentition: On each of the two lower jaw bone, there is a sharp, fang- like extension. The maxilla bears two rows of sharp, backward curved teeth. Behind the posterior nares are two small groups of palate teeth that are close together.

Occurrence

Odontobatrachus natator is indigenous to the rain forests of West Africa. In Sierra Leone, Liberia in the north, in the west of Ivory Coast and Guinea to the south it occurs in the hilly terrain and forested mountain ranges at altitudes of 1400 meters. This is the first vertebrate family, which is endemic in West Africa.

Way of life

Odontobatrachus natator lives in fast-flowing waters and waterfalls, where the tadpoles develop. Because of their lifestyle, some very similar looking frogs were collected as rapids frogs (german torrent frogs ) into its own family Petropedetidae. However, it turned out that these frogs are phylogenetically not so closely related as previously thought. Therefore, the genus occurring in India Indirana was spun off into its own family called Ranixalidae in 2006. The genus Conraua 2011 received the rank of a separate family. Only the genera Petropedetes and Arthroleptides remained within the Petropedetidae. For the originally natator as Petropedetes also classified in the genus Petropedetes Odontobatrachus natator own family was erected in 2014 as well.

History of development

The different types of rapids frogs have a convergent evolution behind it, which has led to the formation of morphologically similar features because of their similar life in the fast flowing water. These frogs need not be closely related. Before the use of molecular genetic methods for investigating phylogenetic relationships external features were often misjudged. This led to the compilation of " hunt groups " that can be systematically divided only recently. For the line of development of Odontobatrachus natator a separation of the other families was calculated already for the Cretaceous period, ie within the Mesozoic more than 65 million years ago.