West African armored crocodile
| West African armored crocodile | ||||||||||||
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West African armored crocodile ( Mecistops cataphractus ) |
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| Mecistops cataphractus | ||||||||||||
| ( Cuvier , 1825) |
The West African armored crocodile ( Mecistops cataphractus ) is an African species of the real crocodiles (Crocodylidae) within the genus Mecistops . Until 2018, Mecistops cataphractus was the only species of the genus, due to differences in DNA and other characteristics, it is now differentiated as the West African armored crocodile from the Central African armored crocodile ( Mecistops leptorhynchus ).
features
The armored crocodile catches the eye with its narrow snout and in this way can be distinguished very quickly from the Nile crocodile ( Crocodylus niloticus ), with which it shares parts of the habitat. Another characteristic of this species are the enlarged neck shields, which are divided into three to four rows of two shields each and are connected to the back plates. In addition to a body drawing, this crocodile also has a drawing of the jaw , which is more reminiscent of the caimans and the Sunda gavial ( Tomistoma schlegelii ).
In contrast to the monochrome jaw of the Central African armored crocodile, the lower jaw of the West African armored crocodile usually shows some dark spots. The head and skull of the West African armored crocodile are slightly wider than that of the Central African armored crocodile, and the front edge of the premaxillary is not perforated as often by the first pair of lower jaw teeth as in the Central African armored crocodile.
distribution and habitat
The West African armored crocodile occurs in West Africa from the Gambia River in the west to the Niger Delta in the east. Little is known about the exact distribution today, as it is mostly hidden in the tropical forests. It lives in medium and large rivers, lakes, papyrus swamps, and other flooded areas, and in small watercourses within larger wetlands. On the coast it also occurs in lagoons with low salinity and in river mouths, but avoids beach areas with open sea access. It occurs only in wooded areas or on rivers that are accompanied by gallery forests, e.g. B. on the Gambia, on the Mole River in northern Ghana or in the Comoé National Park in the northeast of the Ivory Coast. The West African armored crocodile is highly aquatic and cannot reach isolated wetlands.
Way of life
Almost all of the data on the reproduction of armored crocodiles come from a single study from 1985 in the Ivory Coast state . It was found that the breeding season lasts over the entire rainy season from March to July and so some young animals are already hatching, while in other places the eggs are only laid. The eggs are laid in mound nests made of plant material on the banks of smaller forest rivers, which are regularly flooded. Such a clutch contains 13 to 27 eggs per nest. The young hatch during such a flood and in this way get directly into the water. In captivity, it has been observed that a mother is defending her nest. No more is known about brood care for this species.
Exact studies on the diet of the West African armored crocodile are not available. Due to their narrow snouts, it is assumed that they primarily eat fish. In addition, water birds, crustaceans and snakes are eaten, larger specimens could also prey on duikers , stag piglets , gorse and civet cats and monkeys. Young animals feed on insects and frogs and their larvae. There are no confirmed reports that the West African armored crocodile attacks and eats humans.
Systematics
The armored crocodile was first described in 1825 by the French zoologist and paleontologist Frédéric Cuvier under the name Crocodilus cataphractus and assigned to the genus Mecistops in 1844 by the British zoologist John Edward Gray .
DNA comparisons and exact investigations of the skull morphology show, however, that there are at least two species ( cryptospecies ) that can not be distinguished from the outside or can hardly be distinguished from each other. 7.5 to 6.5 million years ago, the resulting Cameroon line , a volcanic mountain range in Central Africa, isolated from each other ( allopatric speciation ). One species lives west of the Cameroon Line in Upper Guinea , the other southeast of it in Lower Guinea and in the Congo Basin . Because of these differences, the West African armored crocodile has been differentiated from the Central African armored crocodile ( Mecistops leptorhynchus ) since 2018 .
supporting documents
- ^ A b c d Matthew H. Shirley, Amanda N. Carr, Jennifer H. Nestler, Kent A. Vliet, Christopher A. Brochu: Systematic revision of the living African Slender-snouted Crocodiles (Mecistops Gray, 1844). In: Zootaxa . 4504, 2018, p. 151, doi: 10.11646 / zootaxa.4504.2.1 .
- ^ John Edward Gray: Catalog of the tortoises, crocodiles, and amphisbaenians, in the collection of the British Museum , Page (s): vii + 80, Trustees of the British Museum (Natural History), London, UK, 1844.
- ^ MH Shirley, KA Vliet, AN Carr, JD Austin. Rigorous approaches to species delimitation have significant implications for African crocodilian systematics and conservation. Proceedings of the Royal Society B: Biological Sciences, 2013; 281 (1776): 20132483, doi: 10.1098 / rspb.2013.2483 .
literature
- Charles A. Ross (Ed.): Crocodiles and Alligators - Evolution, Biology and Distribution. Orbis Verlag, Niedernhausen 2002.
- Joachim Brock: Crocodiles - A life with armored lizards. Natur und Tier Verlag, Münster 1998.
Web links
- Mecistops cataphractus in The Reptile Database
- WWF Conservation Stamp Collection
- Mecistops cataphractus in the endangered Red List species the IUCN 2018 Posted by: Matthew H. Shirley, 2013.