Archeolemur ( lat. Archaeolemuridae ) is a family of extinct lemurs living in Madagascar in the Pleistocene and Holocene . They represented the archaic form of lemurs, adapted to the terrestrial and semi-terrestrial way of life.
Archaeolemur edwardsi face reconstruction
|Archaeolemuridae G. Grandidier , 1905|
Classification and Origin
|The place of archeolemors in the evolution of lemur-like   |
Both known genera of the archaeolemural family - archeolemurs and hydrostrophyses - were already described at the end of the 19th century. The structure of the teeth and a number of other archaic characteristics ( see Anatomy ) suggest that archaeo-lemur descended from a primitive ancestor, common also to indrievs that have survived to the present and another extinct family, the paleopropitecus . At the same time, apparently, the archaeolemuros split off from the main branch of evolution earlier than its division into indrievs and paleopropitekovs. The appearance of the common ancestor was reconstructed in 1988; this hypothetical lemur should have been versatilous and capable of both terrestrial and arboreal lifestyle, and later its descendants specialized. Nevertheless, the phylogenetic relationship between these families has been recognized for a long time. Already a year after the discovery of the skull, the individual, subsequently classified as Archaeolemur majori , was given the generic name Protoindri  . Some sources view archeolemur and paleopropitekov as a subfamily of indrievs  . In the 21st century, the analysis of fossil DNA made it possible to unequivocally establish that the archaeo-lemur specimens were close relatives of the indrievs  .
Archeolemors were large lemurs weighing from 15 to 25 kilograms  . The skull of the archaeoemur is generally similar to the skull of the indrieic , but there are significant differences in the structure of the skeleton, indicating adaptation at the same time to the ground (the structure of the elbow joint, weakly developed forelimb fingers) and arboreal (grasping hand of the hind limb) lifestyle  .
Dental formula 22.214.171.124 , common to both known archeolem genera, is more archaic than that of indrievs. Apparently, the third premolar , which is absent from the indriyevs, is preserved in the archeolemors of their common ancestor. The incisors of archeolemors are larger than those of indriaceae, and the chinous symphysis , as well as paleopropitekov , is tougher and more massive  . Also primitive is the device of the ear canal and middle ear . Large eye sockets are directed forward, in all likelihood, there were vibrissae .
Dissemination and ecology
The remains of archeolemurs are known from more than 20 locations throughout Madagascar , primarily its western part. The remains of the hadropites are found in the west and north-west of the island.
Archeolemurs, the more primitive of the two genera, apparently led a semi-woody lifestyle, like the modern marmoset ( Cercopithecinae ), and the hydrotherapy was a highly specialized terrestrial species, which may indicate adaptability to habitat conditions other than tropical forests. The structure of the optic canal and the size of the orbits suggest that the hadropethecus, which had less sharpness of sight and greater light sensitivity than the archaeolemurs, were nocturnal. Weaning, apparently, occurred in these species later than in megaladapuses and in particular than in paleopropitekov , but later than in modern gorillas and baboons , and coincided with a fairly early appearance of permanent teeth. The dental system of the hadropites, like the modern heladas , was adapted for chewing on hard herbal and deciduous masses along with hard seeds. Perhaps the diet of the hropropitekov also included insects. Analysis of the fossilized excrement of the juvenile Archeolemur specimen from the Anzihikeli cave from the north of the island made it possible to establish that the diet of archeolemurs, in addition to plant food, also included small vertebrates and gastropods  .
The well-known remains of the archaeolemur are sub-fossil , that is, relatively recent. The dating of the skeletal remains of archeolemurs places them in the period from the beginning of the first millennium to the new era to the end of the first millennium of the new era; The coprolites associated with the immature individual from the Anzihikeli locality date back to approximately the end of the 11th – 12th centuries of the new era  . In other words, archeolemurs died out much later than the appearance of people on the island. Such datings for terrestrial and semi-terrestrial species, independent in their existence from tropical forests and extinct giant lemurs extinct simultaneously with tree species, suggest that for those and for others, the destruction of the human habitat did not become a key factor of extinction. At the same time, possible extinction factors such as hunting (the largest of the known lemurs disappeared) and abrupt climate changes cannot be ruled out.
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- Archeolemours on the site of "The Age of Mammals"