False Potto
Encyclopedia
The false potto is a lorisiform
primate of uncertain taxonomic
status found in Africa. Anthropologist Jeffrey H. Schwartz
named it in 1996 as the only species of the genus Pseudopotto on the basis of two specimens (consisting only of skeletal material) that had previously been identified as potto
s (Perodicticus potto). The precise provenances of the two specimens are uncertain, but at least one may have come from Cameroon
. Schwartz thought the false potto could even represent a separate family, but other researchers have argued that the supposed distinguishing features of the animal do not actually distinguish it from the potto; specifically, the false potto shares several features with West African pottos.
The false potto generally resembles a small potto, but according to Schwartz it differs in having a longer tail, shorter spines on its neck and chest vertebrae, a smaller, less complex spine on the second neck vertebra, an entepicondylar foramen
(an opening in the humerus
, or upper arm bone), a lacrimal fossa (a depression in the skull) that is located inside the eye socket, a smaller upper third premolar and molar, and higher-crowned cheekteeth, among other traits. However, many of these traits are variable among pottos; for example, one researcher found entepicondylar foramina in almost half of the specimens in his sample of pottos.
(Perodicticus potto) skeletons in the collections of the Anthropological Institute and Museum of the University of Zurich
at Irchel, anthropologist Jeffrey H. Schwartz
recognized two specimens with traits he believed distinct from all pottos, and in 1996 he used these two specimens to describe a new genus and species of primate, Pseudopotto martini. The generic name, Pseudopotto, combines the element pseudo- (Greek for "false") with "potto", referring to superficial similarities between the new form and the potto. The specific name, martini, honors primatologist Robert D. Martin. The exact provenance of the two specimens is unknown, and one is represented by a complete skeleton (but no skin) and the other by a skull only. Schwartz placed both specimens in a single species, but noted that further study might indicate that the two represent distinct species. He thought the relationships of the new form were unknown and difficult to assess and did not assign it to any family
, but provisionally placed it closest to the family Lorisidae
, together with the potto, the angwantibo
s, and the loris
es. The discovery, published in the Anthropological Papers of the American Museum of Natural History, was featured in Scientific American
and Science
; the Science account noted that Schwartz thought Pseudopotto may represent a new family of primates.
In 1998, the journal African Primates published three papers by primatologists on the false potto. Colin Groves
affirmed that it was probably distinct from the potto and Simon Bearder cited it as an example of unrecognized taxonomic diversity in lorisids, but Esteban Sarmiento
compared the new taxon to specimens of the potto and found that the alleged distinctive traits of the false potto in fact fell within the range of variation of the potto, and that the false potto was probably not even a species distinct from Perodicticus potto. In 2000, primatologist B.S. Leon agreed that the false potto was not distinct from the subspecies
Perodicticus potto potto, but noted that various forms of potto were distinct enough from each other that there may indeed be more than one species of potto. Opinions since then have been divided: a 2003 compilation of African primate diversity concluded that there was insufficient evidence that the false potto is a distinct species, the primate chapter of the 2005 third edition of Mammal Species of the World
, written by Groves, listed Pseudopotto as a genus but noted that it was "controversial"; and Schwartz continued to recognized the false potto as a genus in 2005. Also in 2005, primatologist David Stump reviewed some of the distinguishing features of Pseudopotto in the context of studying variation among pottos, and found that some but not all of the false potto's traits were found in some pottos, mainly western populations (subspecies potto).
One of the specimens, AMZ 6698, is an adult female that lived in Zürich Zoo. It is represented by a virtually complete skeleton, but the skin was not preserved. According to Schwartz, the skeleton shows signs of osteoporosis
and periodontitis (common in zoo animals), but not of other pathologies or abnormalities. The right teeth were removed before Schwartz studied the specimen. Schwartz selected this specimen as the holotype
. The other specimen, AMZ-AS 1730, is a subadult male collected in the wild, of which only the skull, including the mandible (lower jaw), was preserved. The dentition includes both permanent and deciduous teeth. Specimens of Pseudopotto are at least superficially similar to pottos, but according to Schwartz, they differ in a number of traits. Among lorisids, Schwartz saw similarities between the false potto and true pottos as well as angwantibos and slow loris
es (Nycticebus). The false potto is comparable in size to the smallest pottos, but falls within their range of metrical variation; small size is also seen in western pottos.
The tail, according to Schwartz, is longer than in the potto. He does not provide measurements of the tail of AMZ 6698 and notes that at least one vertebra is missing, but Sarmiento counted 11 caudal vertebrae in an illustration of AMZ 6698 and Groves counted at least 15. However, Sarmiento found that the number of caudal vertebrae ranges from 5 to 17, with an average of 11, in pottos. Relatively long tails are also common in the western form of the potto,, though according to Stump the tail of Pseudopotto is longer than any seen in pottos. The false potto allegedly has shorter spines on its cervical (neck) and first and second thoracic (chest) vertebrae, but Leon notes that this feature is also seen in western pottos. Schwartz writes that the false potto differs from pottos and angwantibos in lacking a bifid (two-tipped) spine on the second cervical vertebra, but Sarmiento found this feature in 3 out of 11 potto specimens he examined.
The ulnar styloid process
(a projection on the ulna
, one of the bones of the forearm, where it meets the wrist) is not as hooked as in other lorisids, according to Schwartz, which Groves suggests may indicate that the wrist is more mobile. Another alleged diagnostic feature is the presence of an entepicondylar foramen
(an opening near the distal, or far, end of the bone) on the humerus
(upper arm bone); however, Sarmiento found this feature in 4 out of 11 specimens, and on one side of a fifth, and Stump noted that the foramen occurred in specimens from across the potto's range.
The lacrimal fossa, a depression in the skull, is located on the upper surface of the skull in most lorisids, but Schwartz found that it was further to the back, inside the orbit
(eye socket) in the false potto and the slow loris. Sarmiento found this feature in 3 out of 11 pottos examined. The coronoid process of the mandible
is said to be more hooked in the false potto than in the potto and slow loris.
Other distinguishing features of the false potto are in the dentition. Sarmiento notes, however, that captive specimens may develop abnormalities in the teeth and that some dental characters Schwartz uses are quite variable, sometimes even from one side of the same individual to another. The third upper molar
(M3) is more reduced in the false potto than in any other prosimian
, according to Schwartz, but Leon notes that western pottos also have a relatively small M3. The third upper premolar
(P3) is also reduced, resembling the condition in the fork-marked lemurs (Phaner). Stump writes that small P3s are also common in western pottos, although the false potto's P3 is shaped differently. Groves notes that P1 is quite long, another point of similarity with the fork-marked lemurs. The lower premolars are compressed laterally in Pseudopotto, the cusps
on the cheekteeth are higher, and the cristid obliqua (a crest connected to the protoconid cusp) is at a relatively buccal position (in the direction of the cheeks).
In AMZ 6698, skull length is 59.30 mm (2.335 in) and length of the right humerus is 57.65 mm (2.27 in).
". According to mammalogist Ronald Nowak, these designations imply that the latter came either from modern Cameroon
or far eastern Nigeria
and the former from Cameroon or a neighboring state. In 1999, Simon Bearder claimed, citing a personal communication by C. Wild, that Pseudopotto had been seen in the wild and in 2001, ornithologist Christopher Bowden noted the occurrence of Pseudopotto on Mount Kupe in Cameroon, also citing C. Wild. However, the IUCN Red List
notes that while sightings of the false potto at 820 to 940 m (2690 to 3080 ft) on Mount Kupe had been reported, surveys had failed to confirm its occurrence there, though pottos, some with long tails, had been found. The false potto is not listed separately from the potto in the Red List, because the evidence that it is a distinct species is considered insufficient.
Lorisiformes
Lorisiformes are a group of primates found throughout Africa and Asia. Members of this infraorder include the galagos and the lorises. As strepsirrhines, they are related to the lemurs.* Order Primates** Suborder Strepsirrhini: non-tarsier prosimians...
primate of uncertain taxonomic
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...
status found in Africa. Anthropologist Jeffrey H. Schwartz
Jeffrey H. Schwartz
Jeffrey Hugh Schwartz, PhD, is an American physical anthropologist and professor of biological anthropology at the University of Pittsburgh in Pittsburgh, Pennsylvania, President of the World Academy of Art and Science ....
named it in 1996 as the only species of the genus Pseudopotto on the basis of two specimens (consisting only of skeletal material) that had previously been identified as potto
Potto
The potto is a strepsirrhine primate from the Lorisidae family. It is the only species in genus Perodicticus...
s (Perodicticus potto). The precise provenances of the two specimens are uncertain, but at least one may have come from Cameroon
Cameroon
Cameroon, officially the Republic of Cameroon , is a country in west Central Africa. It is bordered by Nigeria to the west; Chad to the northeast; the Central African Republic to the east; and Equatorial Guinea, Gabon, and the Republic of the Congo to the south. Cameroon's coastline lies on the...
. Schwartz thought the false potto could even represent a separate family, but other researchers have argued that the supposed distinguishing features of the animal do not actually distinguish it from the potto; specifically, the false potto shares several features with West African pottos.
The false potto generally resembles a small potto, but according to Schwartz it differs in having a longer tail, shorter spines on its neck and chest vertebrae, a smaller, less complex spine on the second neck vertebra, an entepicondylar foramen
Entepicondylar foramen
The entepicondylar foramen is an opening in the distal end of the humerus present in some mammals. It is often present in primitive placentals, such as the enigmatic Madagascan Plesiorycteropus...
(an opening in the humerus
Humerus
The humerus is a long bone in the arm or forelimb that runs from the shoulder to the elbow....
, or upper arm bone), a lacrimal fossa (a depression in the skull) that is located inside the eye socket, a smaller upper third premolar and molar, and higher-crowned cheekteeth, among other traits. However, many of these traits are variable among pottos; for example, one researcher found entepicondylar foramina in almost half of the specimens in his sample of pottos.
Taxonomy
In a series of pottoPotto
The potto is a strepsirrhine primate from the Lorisidae family. It is the only species in genus Perodicticus...
(Perodicticus potto) skeletons in the collections of the Anthropological Institute and Museum of the University of Zurich
University of Zurich
The University of Zurich , located in the city of Zurich, is the largest university in Switzerland, with over 25,000 students. It was founded in 1833 from the existing colleges of theology, law, medicine and a new faculty of philosophy....
at Irchel, anthropologist Jeffrey H. Schwartz
Jeffrey H. Schwartz
Jeffrey Hugh Schwartz, PhD, is an American physical anthropologist and professor of biological anthropology at the University of Pittsburgh in Pittsburgh, Pennsylvania, President of the World Academy of Art and Science ....
recognized two specimens with traits he believed distinct from all pottos, and in 1996 he used these two specimens to describe a new genus and species of primate, Pseudopotto martini. The generic name, Pseudopotto, combines the element pseudo- (Greek for "false") with "potto", referring to superficial similarities between the new form and the potto. The specific name, martini, honors primatologist Robert D. Martin. The exact provenance of the two specimens is unknown, and one is represented by a complete skeleton (but no skin) and the other by a skull only. Schwartz placed both specimens in a single species, but noted that further study might indicate that the two represent distinct species. He thought the relationships of the new form were unknown and difficult to assess and did not assign it to any family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
, but provisionally placed it closest to the family Lorisidae
Lorisidae
Lorisidae is a family of strepsirrhine primates. The lorisids are all slim arboreal animals and include the lorises, pottos and angwantibos. Lorisids live in tropical, central Africa as well as in south and southeast Asia....
, together with the potto, the angwantibo
Angwantibo
The angwantibos are the two species of strepsirrhine primates that are classified in the Arctocebus genus of the Lorisidae family. They are also known as golden pottos because of their yellow or golden coloration....
s, and the loris
Loris
Loris is the common name for the strepsirrhine primates of the subfamily Lorisinae in family Lorisidae. Loris is one genus in this subfamily and includes the slender lorises, while Nycticebus is the genus for the slow lorises....
es. The discovery, published in the Anthropological Papers of the American Museum of Natural History, was featured in Scientific American
Scientific American
Scientific American is a popular science magazine. It is notable for its long history of presenting science monthly to an educated but not necessarily scientific public, through its careful attention to the clarity of its text as well as the quality of its specially commissioned color graphics...
and Science
Science (journal)
Science is the academic journal of the American Association for the Advancement of Science and is one of the world's top scientific journals....
; the Science account noted that Schwartz thought Pseudopotto may represent a new family of primates.
In 1998, the journal African Primates published three papers by primatologists on the false potto. Colin Groves
Colin Groves
Colin Peter Groves is Professor of Biological Anthropology at the Australian National University in Canberra, Australia.Born in England on 24 June 1942, Colin Groves completed a Bachelor of Science at University College London in 1963, and a Doctor of Philosophy at the Royal Free Hospital School of...
affirmed that it was probably distinct from the potto and Simon Bearder cited it as an example of unrecognized taxonomic diversity in lorisids, but Esteban Sarmiento
Esteban Sarmiento
Esteban Sarmiento is a primatologist and functional anatomist. His main field of study is the skeletons of hominoids, both extinct species and extant species....
compared the new taxon to specimens of the potto and found that the alleged distinctive traits of the false potto in fact fell within the range of variation of the potto, and that the false potto was probably not even a species distinct from Perodicticus potto. In 2000, primatologist B.S. Leon agreed that the false potto was not distinct from the subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
Perodicticus potto potto, but noted that various forms of potto were distinct enough from each other that there may indeed be more than one species of potto. Opinions since then have been divided: a 2003 compilation of African primate diversity concluded that there was insufficient evidence that the false potto is a distinct species, the primate chapter of the 2005 third edition of Mammal Species of the World
Mammal Species of the World
Mammal Species of the World, now in its 3rd edition, is a standard reference work in zoology giving descriptions and bibliographic data for the known species of mammals.An updated Third Edition of Mammal Species of the World was published late in 2005:...
, written by Groves, listed Pseudopotto as a genus but noted that it was "controversial"; and Schwartz continued to recognized the false potto as a genus in 2005. Also in 2005, primatologist David Stump reviewed some of the distinguishing features of Pseudopotto in the context of studying variation among pottos, and found that some but not all of the false potto's traits were found in some pottos, mainly western populations (subspecies potto).
Description
Osteoporosis
Osteoporosis is a disease of bones that leads to an increased risk of fracture. In osteoporosis the bone mineral density is reduced, bone microarchitecture is deteriorating, and the amount and variety of proteins in bone is altered...
and periodontitis (common in zoo animals), but not of other pathologies or abnormalities. The right teeth were removed before Schwartz studied the specimen. Schwartz selected this specimen as the holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
. The other specimen, AMZ-AS 1730, is a subadult male collected in the wild, of which only the skull, including the mandible (lower jaw), was preserved. The dentition includes both permanent and deciduous teeth. Specimens of Pseudopotto are at least superficially similar to pottos, but according to Schwartz, they differ in a number of traits. Among lorisids, Schwartz saw similarities between the false potto and true pottos as well as angwantibos and slow loris
Slow loris
Slow lorises are a group of five species of strepsirrhine primates which make up the genus Nycticebus. Found in South and Southeast Asia, they range from Northeast India in the west to the Philippines in the east, and from the Yunnan province in China in the north to the island of Java in the south...
es (Nycticebus). The false potto is comparable in size to the smallest pottos, but falls within their range of metrical variation; small size is also seen in western pottos.
The tail, according to Schwartz, is longer than in the potto. He does not provide measurements of the tail of AMZ 6698 and notes that at least one vertebra is missing, but Sarmiento counted 11 caudal vertebrae in an illustration of AMZ 6698 and Groves counted at least 15. However, Sarmiento found that the number of caudal vertebrae ranges from 5 to 17, with an average of 11, in pottos. Relatively long tails are also common in the western form of the potto,, though according to Stump the tail of Pseudopotto is longer than any seen in pottos. The false potto allegedly has shorter spines on its cervical (neck) and first and second thoracic (chest) vertebrae, but Leon notes that this feature is also seen in western pottos. Schwartz writes that the false potto differs from pottos and angwantibos in lacking a bifid (two-tipped) spine on the second cervical vertebra, but Sarmiento found this feature in 3 out of 11 potto specimens he examined.
The ulnar styloid process
Ulnar styloid process
The styloid process of the ulna projects from the medial and back part of the bone; it descends a little lower than the head, and its rounded end affords attachment to the ulnar collateral ligament of the wrist-joint....
(a projection on the ulna
Ulna
The ulna is one of the two long bones in the forearm, the other being the radius. It is prismatic in form and runs parallel to the radius, which is shorter and smaller. In anatomical position The ulna is one of the two long bones in the forearm, the other being the radius. It is prismatic in form...
, one of the bones of the forearm, where it meets the wrist) is not as hooked as in other lorisids, according to Schwartz, which Groves suggests may indicate that the wrist is more mobile. Another alleged diagnostic feature is the presence of an entepicondylar foramen
Entepicondylar foramen
The entepicondylar foramen is an opening in the distal end of the humerus present in some mammals. It is often present in primitive placentals, such as the enigmatic Madagascan Plesiorycteropus...
(an opening near the distal, or far, end of the bone) on the humerus
Humerus
The humerus is a long bone in the arm or forelimb that runs from the shoulder to the elbow....
(upper arm bone); however, Sarmiento found this feature in 4 out of 11 specimens, and on one side of a fifth, and Stump noted that the foramen occurred in specimens from across the potto's range.
The lacrimal fossa, a depression in the skull, is located on the upper surface of the skull in most lorisids, but Schwartz found that it was further to the back, inside the orbit
Orbit (anatomy)
In anatomy, the orbit is the cavity or socket of the skull in which the eye and its appendages are situated. "Orbit" can refer to the bony socket, or it can also be used to imply the contents...
(eye socket) in the false potto and the slow loris. Sarmiento found this feature in 3 out of 11 pottos examined. The coronoid process of the mandible
Coronoid process of the mandible
The mandible's coronoid process is a thin, triangular eminence, which is flattened from side to side and varies in shape and size....
is said to be more hooked in the false potto than in the potto and slow loris.
Other distinguishing features of the false potto are in the dentition. Sarmiento notes, however, that captive specimens may develop abnormalities in the teeth and that some dental characters Schwartz uses are quite variable, sometimes even from one side of the same individual to another. The third upper molar
Molar (tooth)
Molars are the rearmost and most complicated kind of tooth in most mammals. In many mammals they grind food; hence the Latin name mola, "millstone"....
(M3) is more reduced in the false potto than in any other prosimian
Prosimian
Prosimians are a grouping of mammals defined as being primates, but not monkeys or apes. They include, among others, lemurs, bushbabies, and tarsiers. They are considered to have characteristics that are more primitive than those of monkeys and apes. Prosimians are the only primates native to...
, according to Schwartz, but Leon notes that western pottos also have a relatively small M3. The third upper premolar
Premolar
The premolar teeth or bicuspids are transitional teeth located between the canine and molar teeth. In humans, there are two premolars per quadrant, making eight premolars total in the mouth. They have at least two cusps. Premolars can be considered as a 'transitional tooth' during chewing, or...
(P3) is also reduced, resembling the condition in the fork-marked lemurs (Phaner). Stump writes that small P3s are also common in western pottos, although the false potto's P3 is shaped differently. Groves notes that P1 is quite long, another point of similarity with the fork-marked lemurs. The lower premolars are compressed laterally in Pseudopotto, the cusps
Cusp (dentistry)
A cusp is an occlusal or incisal eminence on a tooth.Canine teeth, otherwise known as cuspids, each possess a single cusp, while premolars, otherwise known as bicuspids, possess two each. Molars normally possess either four or five cusps...
on the cheekteeth are higher, and the cristid obliqua (a crest connected to the protoconid cusp) is at a relatively buccal position (in the direction of the cheeks).
In AMZ 6698, skull length is 59.30 mm (2.335 in) and length of the right humerus is 57.65 mm (2.27 in).
Distribution and status
According to records in the Anthropological Institute and Museum, AMZ 6698, the holotype, is from "Equatorial Africa", and AMZ-AS 1730 is from the "CameroonsCameroons
British Cameroons was a British Mandate territory in West Africa, now divided between Nigeria and Cameroon.The area of present-day Cameroon was claimed by Germany as a protectorate during the "Scramble for Africa" at the end of the 19th century...
". According to mammalogist Ronald Nowak, these designations imply that the latter came either from modern Cameroon
Cameroon
Cameroon, officially the Republic of Cameroon , is a country in west Central Africa. It is bordered by Nigeria to the west; Chad to the northeast; the Central African Republic to the east; and Equatorial Guinea, Gabon, and the Republic of the Congo to the south. Cameroon's coastline lies on the...
or far eastern Nigeria
Nigeria
Nigeria , officially the Federal Republic of Nigeria, is a federal constitutional republic comprising 36 states and its Federal Capital Territory, Abuja. The country is located in West Africa and shares land borders with the Republic of Benin in the west, Chad and Cameroon in the east, and Niger in...
and the former from Cameroon or a neighboring state. In 1999, Simon Bearder claimed, citing a personal communication by C. Wild, that Pseudopotto had been seen in the wild and in 2001, ornithologist Christopher Bowden noted the occurrence of Pseudopotto on Mount Kupe in Cameroon, also citing C. Wild. However, the IUCN Red List
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
notes that while sightings of the false potto at 820 to 940 m (2690 to 3080 ft) on Mount Kupe had been reported, surveys had failed to confirm its occurrence there, though pottos, some with long tails, had been found. The false potto is not listed separately from the potto in the Red List, because the evidence that it is a distinct species is considered insufficient.