long-tailed loris

 The enigma of the long-tailed lory 

  Sometimes there are species that are seen only once and are never heard from again, and of which no trace is seen again, such as the case that we will see below.

The slow-tailed lory or long-tailed lemur,(proposed name: Nycticebus caudatus sp. nov.), was a mysterious primate of the suborder Strepsirrhini, which has been reported from the Lushai Hills, 

  The existence of this primate was reported by the zoologist Nelson Annandale (1876 -1924), superintendent of the Indian Museum in the Proceedings of the Zoological Society of London in 1908, when he had been sent photographs of two captive specimens, captured by Thomas Henry Digges of the Geological Survey of India.

 Touche who told Annandale that two of these had been captured in December 1889, during the Lushai Expedition of 1889-1890, by a group exploring the jungle near Fort Lungleh, near took a single photograph of the couple, who were caged for some time; However, due to their slow movements, they did not take measures to prevent their escape and in Consequently, "once they got out of their cage, they quickly disappeared", here we have the photograph.

  The defining characteristic of these is their tail, which is long and bushy, similar to that of a chinchilla, Annandale described it as "very thick and cylindrical, shorter than the head and body, and body, He speculated that the tail might be prehensile, as both captive specimens were photographed with the tail curled close to the body. 

According to Annandale, its eyes may be slightly smaller than those of the Sunda slow loris (Nycticebus coucang), having a whitish, "narrow and woolly" coat, with a narrow black stripe down the back, as well as dark ears and eye patches.

Assam Mountains 

  To date there are eight widely recognized living species of Loris, and all are virtually tailless, with tails plump hidden by their fur coats, of these species, only one of them is recorded in India: the Bengal slow lory,

(Nycticebus bengalensis)

According to research, it may be possible that the reactivation of an atavistic gene has promoted the growth of an ancestral tail in some individuals of this species, turning tailed slow lorises into an isolated group of teratological mutants.

Although this is considered the most likely explanation, it is noted that the other possibility is that the animals photographed must represent an undiscovered species, for which the parataxonomic name Nycticebus caudatus was proposed.

 Regardless of whether this was a mutation or an undescribed species, it is suggested that slow-tailed lorises probably disappeared at the beginning of the 20th century, given the lack of later reports, it is somewhat frustrating to see how species so interesting were lost without their existence being known, since 121 years have passed since they were last seen.

References:

Annandale, Nelson "An unknown lemur from the Lushai Hills, Assam", Proceedings of the Zoological Society of London (1908)