Brookesia micra
Brookesia micra ♂ in peace coloring
Brookesia micra is a kind of stubby tail chameleons ( Brookesiinae ). The 23-29 mm long member of the genus Brookesia is the smallest known reptile in the world. Brookesia micra is found only on the island of Nosy Hara in the north of Madagascar. There, the species inhabits the bottom area of dry forests.
Brookesia micra was discovered in 2007 during an expedition to Nosy Hara and described in 2012 by a group of researchers from the Zoological State Collection Munich under the direction of the zoologist Frank Glaw. It belongs to a group of very small Brookesia species from the extreme north of Madagascar.
Features
Brookesia micra is an extremely small and petite chameleon. The females of the species have a head -body length of 18.7 to 19.9 mm, overall they are 26.9 to 28.8 mm long. The smaller males are from head to torso from 15.3 to 15.9 mm long and have a total length of 22.5 to 23.6 mm. The tail is 7.2 to 8.9 (females ) or 7.2-7.8 mm (males) proportionally very short even for a Brookesia type. The head is longer than wide. B. micra has pronounced bulging eyes, the eyes measured in the horizontal diameter in females 2.0-2.2 mm and 1.7-2.2 mm in the male. The ridge is where the level of the posterior edges and ends at the base of the tail. B. micra has eleven, twelve rare small spines on each side of the back. In the neck, a helmet is only indicated by a small ridge. The tail is slightly thicker in males than in females.
The body of B. micra is dark brown in the idle state, only on situated before the eyes of the snout is a beige stain. The tail is towards the end always yellow and takes at the top of an orange color. The stress coloration deviates significantly from: The brown body top is interspersed with dark, gray brown spots. Top of the head, back comb and tail are colored light gray-brown under stress and thus stand out from the rest of the back.
The hemipenes of the male, which was prepared as the holotype of the genus, is elongated ( 2.4 mm ), relatively wide ( maximum width 0.9 mm) and transparent. He has no ornaments. The tip consists of a comb-like structure with six papillae, which are the smallest in the middle at the biggest and at the edge. Only one passage hemipenis is everted, the second hemipenis is only partially everted. When not completely everted Hemipenissen the crest at the top is not visible.
Distribution and habitat
Brookesia micra is known only from two locations on the North Island of Madagascar's Nosy Hara. There are two deposits were discovered along a small brook. Whether B. micra beyond is also present in other parts of the island, is unclear. The species was overlooked by extensive herpetological expeditions in the past, suggesting that it is difficult to discover. The habitat of animals consists of the forest floor of a dry forest that grows on eroded limestone rocks.
Way of life
Over the life of the species is little known. During the day, they move on to the limestone blocks and between herabgefallenem leaves in their habitat. At night, the animals pull on branches at low altitude (5-10 cm above the ground) back.
System
B. ramanantsoai
B. exarmata
B. dentata
B. minima
B. karchei
B. peyrierasi
B. tuberculata
B. confidens
B. micra
B. tristis
B. desperata
The first individuals of Brookesia micra were discovered in March 2007 during a zoological expedition to the north of Madagascar. A male was killed for research purposes and preserved as holotype for later species profile. 2008 more animals were measured and photographed during a second expedition in February. In February 2012, finally, the first description in the journal PLoS ONE was published, together with the desperata the related species B. tristis, B. and B. confidens. The authors of the first description, the German zoologist Frank Glaw, Miguel Vences Jörn Köhler and as well as their American colleague Ted M. Townsend. At the time of its discovery Brookesia micra was the smallest known reptile in the world, followed by the epithet micra ( altgr. μικρός microscopic, tiny, small ' ) refers.
Within the genus Brookesia micra as part of the B. minima group, which brings together a number of very small species from northern Madagascar. The species is the sister taxon of a clade formed by B. desperata tristis and B.; both types are located at the northern tip of Madagascar. The ND2 gene of the two clades differ by 23-26 %. Probably the precursor of the two clades were separated by a sea level rise, which made Nosy Hara to the island. The size of B. micra does not result solely from the already small body size of B. minima group, but is also the result of Inselverzwergung.