Tarsiiformes
Encyclopedia
Tarsiiformes are a group of primate
s that was once ranged across Europe, northern Africa, Asia, and North America, but today all living species
are found in the islands of Southeast Asia
. Tarsier
s (family Tarsiidae) are the only living members of the infraorder
, and also include the extinct Tarsius eocaenus from the Eocene
and Tarsius thailandicus from the Miocene
. Two extinct genera, Xanthorhysis and Afrotarsius, are considered to be close relatives of the living tarsiers and are generally classified within Tarsiiformes, with the former grouped within family Tarsiidae and the latter listed as incertae sedis
(undefined). Omomyid
s are generally considered to be extinct relatives, or even ancestors, of the living tarsiers and are often classified within Tarsiiformes. Other fossil primates, which include Microchoeridae, Carpolestidae
, and Eosimiidae
, have been included in this classification, although the fossil evidence is debated. Eosimiidae has also been classified under the infraorder Simiiformes (with monkeys and apes). Likewise, Carpolestidae is often classified within the order Plesiadapiformes
, a very close, extinct relative of primates. These conflicting classifications lie at the heart of the debate over early primate evolution. Even the placement of Tarsiiformes within suborder Haplorrhini
(with the monkey
s and ape
s or "higher primates
") is still debated.
s, galago
s, and loris
es.
Primate
A primate is a mammal of the order Primates , which contains prosimians and simians. Primates arose from ancestors that lived in the trees of tropical forests; many primate characteristics represent adaptations to life in this challenging three-dimensional environment...
s that was once ranged across Europe, northern Africa, Asia, and North America, but today all living species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
are found in the islands of Southeast Asia
Southeast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...
. Tarsier
Tarsier
Tarsiers are haplorrhine primates of the genus Tarsius, a genus in the family Tarsiidae, which is itself the lone extant family within the infraorder Tarsiiformes...
s (family Tarsiidae) are the only living members of the infraorder
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
, and also include the extinct Tarsius eocaenus from the Eocene
Eocene
The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...
and Tarsius thailandicus from the Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
. Two extinct genera, Xanthorhysis and Afrotarsius, are considered to be close relatives of the living tarsiers and are generally classified within Tarsiiformes, with the former grouped within family Tarsiidae and the latter listed as incertae sedis
Incertae sedis
, is a term used to define a taxonomic group where its broader relationships are unknown or undefined. Uncertainty at specific taxonomic levels is attributed by , , and similar terms.-Examples:*The fossil plant Paradinandra suecica could not be assigned to any...
(undefined). Omomyid
Omomyid
Omomyids are a diverse group of early primates that radiated during the Eocene epoch between about 55 and 34 million years ago . Fossils of omomyids are found in North America, Europe, Asia, and possibly Africa...
s are generally considered to be extinct relatives, or even ancestors, of the living tarsiers and are often classified within Tarsiiformes. Other fossil primates, which include Microchoeridae, Carpolestidae
Carpolestidae
Carpolestidae is a family of primate-like Plesiadapiformes that were prevalent in North America and Asia from the mid Paleocene through the early Eocene. Typically, they are characterized by two large upper posterior premolars and one large lower posterior premolar. They weighed about 20-150g, and...
, and Eosimiidae
Eosimiidae
Eosimiidae is the family of extinct primates believed to be the earliest simians....
, have been included in this classification, although the fossil evidence is debated. Eosimiidae has also been classified under the infraorder Simiiformes (with monkeys and apes). Likewise, Carpolestidae is often classified within the order Plesiadapiformes
Plesiadapiformes
Plesiadapiformes is an extinct order of mammals. It is either closely related to the primates or a precursor to them. Many are too derived to be ancestral to primates, but the earliest Plesiadapiformes have teeth that are strongly indicative of a common ancestor...
, a very close, extinct relative of primates. These conflicting classifications lie at the heart of the debate over early primate evolution. Even the placement of Tarsiiformes within suborder Haplorrhini
Haplorrhini
The haplorhines, the "dry-nosed" primates , are members of the Haplorhini clade: the prosimian tarsiers and the anthropoids...
(with the monkey
Monkey
A monkey is a primate, either an Old World monkey or a New World monkey. There are about 260 known living species of monkey. Many are arboreal, although there are species that live primarily on the ground, such as baboons. Monkeys are generally considered to be intelligent. Unlike apes, monkeys...
s and ape
Ape
Apes are Old World anthropoid mammals, more specifically a clade of tailless catarrhine primates, belonging to the biological superfamily Hominoidea. The apes are native to Africa and South-east Asia, although in relatively recent times humans have spread all over the world...
s or "higher primates
Simian
The simians are the "higher primates" familiar to most people: the Old World monkeys and apes, including humans, , and the New World monkeys or platyrrhines. Simians tend to be larger than the "lower primates" or prosimians.- Classification and evolution :The simians are split into three groups...
") is still debated.
Classification
Generally accepted members of this infraorder include the living tarsiers, the extinct omomyids, two extinct fossil genera, and two extinct fossil species within the genus Tarsius. As haplorrhines, they are more closely related to monkeys and apes than to the strepsirrhine primates, which include lemurLemur
Lemurs are a clade of strepsirrhine primates endemic to the island of Madagascar. They are named after the lemures of Roman mythology due to the ghostly vocalizations, reflective eyes, and the nocturnal habits of some species...
s, galago
Galago
Galagos , also known as bushbabies, bush babies or nagapies , are small, nocturnal primates native to continental Africa, and make up the family Galagidae...
s, and 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.
- Order PrimatePrimateA primate is a mammal of the order Primates , which contains prosimians and simians. Primates arose from ancestors that lived in the trees of tropical forests; many primate characteristics represent adaptations to life in this challenging three-dimensional environment...
s- Suborder StrepsirrhiniStrepsirrhiniThe clade Strepsirrhini is one of the two suborders of primates. Madagascar's only non-human primates are strepsirrhines, and others can be found in southeast Asia and Africa...
: lemurs, lorises, and galagos - Suborder HaplorrhiniHaplorrhiniThe haplorhines, the "dry-nosed" primates , are members of the Haplorhini clade: the prosimian tarsiers and the anthropoids...
- Infraorder Simiiformes: monkeys and apes
- Infraorder TarsiiformesTarsiiformesTarsiiformes are a group of primates that was once ranged across Europe, northern Africa, Asia, and North America, but today all living species are found in the islands of Southeast Asia. Tarsiers are the only living members of the infraorder, and also include the extinct Tarsius eocaenus from the...
- Family †Omomyidae
- Family TarsiidaeTarsierTarsiers are haplorrhine primates of the genus Tarsius, a genus in the family Tarsiidae, which is itself the lone extant family within the infraorder Tarsiiformes...
: tarsiers- Genus †Afrotarsius
- Genus †Xanthorhysis
- Genus TarsiusTarsierTarsiers are haplorrhine primates of the genus Tarsius, a genus in the family Tarsiidae, which is itself the lone extant family within the infraorder Tarsiiformes...
- Suborder Strepsirrhini