Amphisbaenia

Moorish Netzwühle ( Blanus cinereus )

The amphisbaenians ( Amphisbaenia: origin ἡ ἀμφίσβαιυ · α ), also called calendula crawl, worm crawl or ringed lizards are a group of strangely reminiscent of earthworms Squamata ( Squamata ). They get their name from amphisbaena, a mythical snake with a head at each end. It refers to the fact that sometimes can not be seen in the animals at first glance, to which end of the body is the head. Previously they were counted as a family to the lizards ( Lacertilia ), but their anatomical features and their long independent evolution meant that they were given the rank of subordination.

One can prove fossil amphisbaenians since the Eocene and Oligocene. At that time they lived on the northern continents, North America, Europe and Asia. With Blanus antiquus were also found a amphisbaenian from the Middle Miocene of southern Germany.

Occurrence

Most of the approximately 150 species live in Africa, South America and the islands of the Caribbean, Florida and the south of Baja California. The genus Blanus lives in the Mediterranean. The 30 cm long Moorish Netzwühle ( Blanus cinereus ) lives on the Iberian Peninsula. Blanus strauchi lives in Rhodes, Kos, Cyprus, western Turkey, Lebanon, Syria and northern Iraq.

Since they are rare and have a grave lifestyle, little is known except their anatomy.

Appearance and anatomy

Amphisbaenians are the most adapted to a subterranean lifestyle Squamata. All but the two-foot - amphisbaenians ( Bipedidae ) are legless. The flakes are gone except for residues at the head. The animals are surrounded by a tough, cross ringed sac, which leads to confusion with earthworms. The stretched body is rotating around, front and rear the same thickness. The head can be blunt or pointed. The mouth is small, the lower jaw is shorter. The animals dig using their strong skull, which has the function of a drill bit. The nostrils point to the rear, so that no earth comes into it. Also, the tail is short and blunt, or pointed. Amphisbaenians not crawl on the type of snakes or crawl with lateral undulations of the body, but, in adapting to their movement in corridors, stretched slowly. In this case, run like earthworms pulse-like wave movements through the body. You can crawl backwards as fast or slow as forward. Amphisbaenians breathe with the enlarged left lung, in contrast to the snakes and all snake-like lizards, in which the right lung function and the left is reduced. They are usually 20 to 30 inches tall. The Red amphisbaenian ( amphisbaena alba) from South America and Monopeltis capensis from Africa are 50 to 70 inches long.

Reproduction

Male amphisbaenians as all Squamata two hemipenes as a copulatory organ. Most species lay eggs, often in termite nests, some species are viviparous.

Nutrition

Ringel Sneak eat worms, millipedes, insects and their larvae, many tropical species feed mainly on ants and termites. The Moorish Netzwühle has a preference for ants.

System

The position of amphisbaenians within the reptiles is still controversial (see also: Squamata ). They are considered monophyletic and are not closely related to the snakes. Some scientists expect it to Skinkartigen ( Scincomorpha ). According to recent molecular biological studies, the amphisbaenians are the sister group of the Real lizards ( Lacertidae ) and form with them a new, Lacertibaenia called taxon. The thesis is supported by the discovery of Cryptolacerta, a small lizard from the Messel pit, whose anatomical characteristics are a mosaic of lizards and amphisbaenians features.

As subordination their rank in the scheme of Squamata is probably overstated. The strong anatomical adaptations to their grave lifestyle meant that the taxonomic rank was considered too high.

The amphisbaenians are now divided into six families:

• Florida amphisbaenians ( Rhineuridae ). Only one species, the Florida amphisbaenian ( Rhineura floridana ) lives in northern Florida to Lake Okeechobee in the Everglades National Park. Systematically, it is available to all other amphisbaenians over as a sister group.
• Actual amphisbaenians ( Amphisbaenidae ). 16 genera, spread in Africa, South America and the Caribbean Islands.
• Pointed tooth - amphisbaenians ( Trogonophidae ). Four genera ( Agamodon, Diplometopon, Pachycalamus, Trogonophis ) with a total of six species in Africa and the Middle East.
• Dual Foot amphisbaenians ( Bipedidae ). The only genre that hand digging ( bipes ) have small remodeled to grave tools forelimbs. They live in western Mexico.
• Cadeidae. A genus occurring in Cuba ( Cadea ) with two species ( Cadea blanoides and Cadea palirostrata ).
• Blanidae. A occurring in the Mediterranean genus ( Blanus ) with four species, including the Moorish Netzwühle ( Blanus cinereus ).

This cladogram shows the phylogenetic relationships within the amphisbaenians:

Florida amphisbaenians ( Rhineuridae )

Actual amphisbaenians ( Amphisbaenidae )

Pointed tooth - amphisbaenians ( Trogonophidae )

Dual Foot amphisbaenians ( Bipedidae )

Cadeidae

Blanidae