''Aphaenogaster donisthorpei'' is an extinct

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

ant Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of ...

in formicid subfamily Myrmicinae known from a

Late 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'', "d ...

fossil from North America. ''A. donisthorpei'' was one of two ''

Aphaenogaster ''Aphaenogaster'' is a genus of myrmicine ants. About 200 species have been described, including 18 fossil species. They occur worldwide except in South America south of Colombia, sub-Saharan Africa, and Antarctica. They are often confused w ...

'' species described in the 1930 paper.

History and classification

''Aphaenogaster donisthorpei'' is known from a solitary fossil insect which is a compression-impression fossil preserved in fine shales of the

Florissant formation The Florissant Formation is a sedimentary geologic formation outcropping around Florissant, Teller County, Colorado. The formation is noted for the abundant and exceptionally preserved insect and plant fossils that are found in the mudstones an ...

in Colorado. The formation is composed of successive lake deposits which have preserved a diverse assemblage of insects. The insects and plants suggest a climate similar to modern Southeastern North America, with a number of taxa represented that are now found in the subtropics to tropics and confined to the old world. When ''A. donisthorpei'' was described, the Florissant formation was considered to be

Miocene The Miocene ( ) is the first epoch (geology), 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 mea ...

in age, based on the flora and fauna preserved. Subsequent research and fossil descriptions re-examined the dating, and by 1985 the formation had been reassigned to an Oligocene age. Further refinement of the formation's age using radiometric dating of sanidine crystals has resulted in an age of 34 million years old. This places the formation in the Late Eocene Priabonian stage. At the time of description the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of sever ...

specimen, number 2917 was deposited in the

Museum of Comparative Zoology A museum ( ; plural museums or, rarely, musea) is a building or institution that cares for and displays a collection of artifacts and other objects of artistic, cultural, historical, or scientific importance. Many public museums make thes ...

paleontology collections at

Harvard University Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of high ...

. Along with a number of other insect type specimens, the ''A. donisthorpei'' holotype is part of the

Samuel Hubbard Scudder Samuel Hubbard Scudder (April 13, 1837 – May 17, 1911) was an American entomologist and paleontologist. He was a leading figure in entomology during his lifetime and the founder of insect paleontology in America. In addition to fossil insects ...

insect collection donated to Harvard in 1902. The fossil was first studied by paleoentomologist Frank M. Carpenter of the Museum of Comparative Zoology; in 1930 his

type description A species description is a formal description of a newly discovered species, usually in the form of a scientific paper. Its purpose is to give a clear description of a new species of organism and explain how it differs from species that have be ...

of the new species was published in the ''Bulletin of the Museum of Comparative Zoology''. The

etymology Etymology ()The New Oxford Dictionary of English (1998) – p. 633 "Etymology /ˌɛtɪˈmɒlədʒi/ the study of the class in words and the way their meanings have changed throughout time". is the study of the history of the Phonological chan ...

for the specific epithet ''donisthorpei'' was not specified with the type description, but

Horace Donisthorpe Horace St. John Kelly Donisthorpe (17 March 1870 – 22 April 1951) was an eccentric British myrmecologist and coleopterist, memorable in part for his enthusiastic championing of the renaming of the genus ''Lasius'' after him as ''Donisthorpea ...

(1870–1951) was a British myrmecologist and coleopterist. ''A. donisthorpei'' was one of two ''Aphaenogaster'' species from the Florissant Formation that Carpenter described in the paper, the other species being ''

Aphaenogaster mayri ''Aphaenogaster mayri'' is an extinct species of ant in Formicidae, formicid subfamily Myrmicinae known from a series of Late Eocene fossils found in North America. ''A. mayri'' was one of two ''Aphaenogaster'' species described in a 1930 paper ...

''.

Description

The ''Aphaenogaster donisthorpei'' specimen is a partially preserved queen caste adult which was fossilized with its dorsal side facing upwards and the attached wings outspread. The overall length of the queen is approximately , the head has an estimated length of and the thorax is estimated at . The antennae are long and slender in appearance, composed of a scape that is extends past the hind margin of the head and

funicular A funicular (, , ) is a type of cable railway system that connects points along a railway track laid on a steep slope. The system is characterized by two counterbalanced carriages (also called cars or trains) permanently attached to opposite e ...

segments which are twice as long are they are wide. The preserved

forewing Insect wings are adult outgrowths of the insect exoskeleton that enable insects to fly. They are found on the second and third thoracic segments (the mesothorax and metathorax), and the two pairs are often referred to as the forewings and hindwi ...

is long and has venation similar to that of ''A. mayri''. The two are distinguished based on the more slender nature of ''A. donisthorpei'' with longer head and thorax proportions.

References

{{Taxonbar, from=Q14445657 donisthorpei Priabonian insects Fossil ant taxa Prehistoric insects of North America Fossil taxa described in 1930 Florissant Formation Taxa named by Frank M. Carpenter