The following sloth family phylogenetic tree is based on collagen and mitochondrial DNA sequence data (see Fig. These results provide further strong support for the long-held belief that arboreality arose separately in the two genera via convergent paths. These investigations consistently place three-toed sloths within Megatherioidea, close to Megalonyx, megatheriids and nothrotheriids, and two-toed sloths close to mylodontids, while moving the Caribbean sloths to a separate, basal branch of the sloth evolutionary tree. Understanding of sloth phylogeny has recently been greatly revised by molecular studies, based on collagen and mitochondrial DNA sequences. The two-toed sloths were thought on the basis of morphology to nest phylogenetically within one of the divisions of ground-dwelling Caribbean sloths. From morphological studies it was unclear from which ground-dwelling sloth taxa the three-toed sloths evolved or whether they retained their arboreality from the last common ancestor of extant sloths. Recent phylogenetic analyses support the morphological data from the 1970s and 1980s that the two genera are not closely related and that each adopted their arboreal lifestyles independently.
Although similar in overall appearance, the two genera are placed in different families. Relation to the two-toed sloth īoth types of sloth tend to occupy the same forests in most areas, a particular species of three-toed sloth and a single species of the somewhat larger and generally faster-moving two-toed sloth will jointly predominate. variegatus lineages was estimated to have started 4 to 5 million years ago. tridactylus about 12 million years ago, while the latter two split 5 to 6 million years ago. Part of northern South America, including Guyana, Suriname, French Guiana, eastern Venezuela and Brazil north of the Amazon RiverĬentral America and much of north and central South America, from Honduras through Colombia, Venezuela, Ecuador, eastern Peru, Bolivia and BrazilĪ study of mitochondrial cytochrome b and 16S rRNA sequences suggests that B.
#Three toed sloth license#
This is a part of the Wikipedia article used under the Creative Commons Attribution-Sharealike 3.0 Unported License (CC-BY-SA).Atlantic coastal rainforest of southeastern Brazil The IUCN lists the pygmy three-toed sloth as critically endangered and they are listed on the world's 100 most threatened species. A 2012 census of pygmy three-toed sloths estimated the total population at 79. The pygmy three-toed sloth is found exclusively in the red mangroves of Isla Escudos de Veraguas, restricted to an area of 4.3 square kilometres. Details of mating behavior and reproduction have not been documented. It is symbiotically associated with green algae, that can provide it with a camouflage. It lives high in the canopy but descends once a week to defecate on the forest floor. It has a body adapted to hang by its limbs the large curved claws help the sloth to keep a strong grip on tree branches. This sloth, like other sloths, is arboreal and feeds on leaves. According to Anderson and Handley Jr., the head-and-body length is between 48 and 53 centimetres, and the body mass ranges from 2.5 to 3.5 kg. The pygmy three-toed sloth is significantly smaller than the other three members of its genus, but otherwise resembles the brown-throated three-toed sloth. Handley Jr., of the Smithsonian Institution in 2001. Anderson of the University of Kansas and Charles O. The species was first described by Robert P. The pygmy three-toed sloth, also known as the monk sloth or dwarf sloth, is a sloth endemic to Isla Escudo de Veraguas, a small island off the Caribbean coast of Panama.