Adapiformes is a group of early

primate Primates are a diverse order of mammals. They are divided into the strepsirrhines, which include the lemurs, galagos, and lorisids, and the haplorhines, which include the tarsiers and the simians ( monkeys and apes, the latter includin ...

s. Adapiforms radiated throughout much of the northern continental mass (now

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an are ...

and

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...

), reaching as far south as northern

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

and tropical Asia. They existed from the

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', ...

to the

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

epoch. Some adapiforms resembled living

lemur Lemurs ( ) (from Latin ''lemures'' – ghosts or spirits) are wet-nosed primates of the superfamily Lemuroidea (), divided into 8 families and consisting of 15 genera and around 100 existing species. They are endemic to the island of Madagas ...

s. Adapiforms are known from the fossil record only, and it is unclear whether they form a

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gr ...

paraphyletic In taxonomy, a group is paraphyletic if it consists of the group's last common ancestor and most of its descendants, excluding a few monophyletic subgroups. The group is said to be paraphyletic ''with respect to'' the excluded subgroups. In ...

group. When assumed to be a

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English ter ...

, they are usually grouped under the "wet-nosed" taxon

Strepsirrhini Strepsirrhini or Strepsirhini (; ) is a suborder of primates that includes the lemuriform primates, which consist of the lemurs of Madagascar, galagos ("bushbabies") and pottos from Africa, and the lorises from India and southeast Asia. Co ...

, which would make them more closely related to the lemurs and less so to the "dry-nosed"

Haplorhini Haplorhini (), the haplorhines ( Greek for "simple-nosed") or the "dry-nosed" primates, is a suborder of primates containing the tarsiers and the simians (Simiiformes or anthropoids), as sister of the Strepsirrhini ("moist-nosed"). The name is so ...

taxon that includes

monkey Monkey is a common name that may refer to most mammals of the infraorder Simiiformes, also known as the simians. Traditionally, all animals in the group now known as simians are counted as monkeys except the apes, which constitutes an incomple ...

s and apes.Callum Ross, Richard F. Kay, ''Anthropoid origins: new visions'', Springer, 2004, , p. 100 In 2009, Franzen and colleagues placed the newly described genus ''

Darwinius ''Darwinius'' is a genus within the infraorder Adapiformes, a group of basal strepsirrhine primates from the middle Eocene epoch. Its only known species, ''Darwinius masillae'', lived approximately 47 million years ago (Lutetian stage) based ...

'' in the "Adapoidea group of early primates representative of early haplorhine diversification" so that, according to these authors, the adapiforms would not be within the Strepsirrhini lineage as hitherto assumed but qualify as a stem "missing link" between Strepsirrhini and Haplorrhini. However, subsequent analysis on the ''Darwinius'' fossil by Erik Seiffert and colleagues rejects this "missing link" idea, classifying ''Darwinius'' and other adapiforms within the Strepsirrhini. Boyer et al. found that the crown Strepsirrhini likely emerged deep in the Adapiformes tree, possibly as sister of a group which include e.g. '' Aframonius'' and

Notharctidae Notharctidae is an extinct family of adapiform primate Primates are a diverse order of mammals. They are divided into the strepsirrhines, which include the lemurs, galagos, and lorisids, and the haplorhines, which include the tarsiers an ...

. The Adapiformes are thus found not to be literally extinct (in the sense of having no living descendants), and becomes a junior synonym to the Strepsirrhini. Below is a simplified cladogram. A 2018 study puts ''Donrussellia'' as sister to crown primates.

Classification

Adapiforms belong to the infraorder Adapiformes, which contains a single superfamily, Adapoidea. The group also is sometimes treated as a superfamily (Adapoidea) alongside the other living

strepsirrhine Strepsirrhini or Strepsirhini (; ) is a suborder of primates that includes the lemuriform primates, which consist of the lemurs of Madagascar, galagos ("bushbabies") and pottos from Africa, and the lorises from India and southeast Asia. Colle ...

superfamilies, Lemuroidea (lemurs) and

Lorisoidea Lorisoidea is a superfamily of nocturnal primates found throughout Africa and Asia. Members include the galagos and the lorisids. As strepsirrhines, lorisoids are related to the lemurs of Madagascar and are sometimes included in the infraorder L ...

(

loris Loris is the common name for the strepsirrhine mammals of the subfamily Lorinae (sometimes spelled Lorisinae) in the family Lorisidae. ''Loris'' is one genus in this subfamily and includes the slender lorises, ''Nycticebus'' is the genus conta ...

es and

galago Galagos , also known as bush babies, or ''nagapies'' (meaning "night monkeys" in Afrikaans), are small nocturnal primates native to continental, sub-Sahara Africa, and make up the family Galagidae (also sometimes called Galagonidae). They are ...

s). *Infraorder Adapiformes **Superfamily Adapoidea ***Family

***Family

Sivaladapidae Sivaladapidae is an extinct family of adapiform primates from Asia. They survived longer than any other adapiform primate because they were able to shift south as the climate cooled. Their remains date from the Eocene through the Miocene The ...

***Family

Adapidae Adapidae is a family of extinct primates that primarily radiated during the Eocene epoch between about 55 and 34 million years ago. Adapid systematics and evolutionary relationships are controversial, but there is fairly good evidence from the ...

*Infraorder ''incertae sedis'' **Superfamily ''incertae sedis'' ***Family

Azibiidae Azibiidae is an extinct family of fossil primate from the late early or early middle Eocene from the Glib Zegdou Formation in the Gour Lazib area of Algeria. They are thought to be related to the living toothcombed primates, the lemurs and lor ...

***Family

Djebelemuridae Djebelemuridae is an extinct family of early strepsirrhine primates from Africa. It consists of five genera. The organisms in this family were exceptionally small, and were insectivores. This family dates to the early to late Eocene. Altho ...

Rose (1995) suggests that early adapiformes and omoyiformes shared a common ancestor dating to the

Thanetian The Thanetian is, in the ICS Geologic timescale, the latest age or uppermost stratigraphic stage of the Paleocene Epoch or Series. It spans the time between . The Thanetian is preceded by the Selandian Age and followed by the Ypresian Age ( ...

age.

References

Sources

* *

External links

Mikko's Phylogeny Archive
{{Taxonbar, from=Q135042 Prehistoric strepsirrhines Eocene first appearances Miocene extinctions Mammal infraorders Fossil taxa described in 1977 Taxa named by Robert Hoffstetter Paraphyletic groups