''Hydriomena''? ''protrita'' 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 ...

moth Moths are a paraphyletic group of insects that includes all members of the order Lepidoptera that are not butterflies, with moths making up the vast majority of the order. There are thought to be approximately 160,000 species of moth, many of w ...

in the family

Geometridae The geometer moths are moths belonging to the family Geometridae of the insect order Lepidoptera, the moths and butterflies. Their scientific name derives from the Ancient Greek ''geo'' γεω (derivative form of or "the earth"), and ''metro ...

, and possibly in the modern genus '' Hydriomena''. The species is known from

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 ...

, Priabonian stage, lake deposits 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 ...

Teller County, Colorado Teller County is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 24,710. The county seat is Cripple Creek, and the most populous city is Woodland Park. Teller County is included in the Colorado Sprin ...

, United States. It was first described by

Theodore Dru Alison Cockerell Theodore Dru Alison Cockerell (1866–1948) was an American zoologist, born at Norwood, England, and brother of Sydney Cockerell. He was educated at the Middlesex Hospital Medical School, and then studied botany in the field in Colorado in 188 ...

in 1922.

History and classification

''Hydriomena''? ''protrita'' is known only from one fossil, 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 "AMNH-FI-19033". It is a single, complete

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 ...

, preserved as a

compression fossil A compression fossil is a fossil preserved in sedimentary rock that has undergone physical compression. While it is uncommon to find animals preserved as good compression fossils, it is very common to find plants preserved this way. The reason f ...

in fine grained shale. The shale specimen is one of a group of fossils obtained in 1909 by George F. Sternberg, Terry Duce, and Willard Rusk from the

, named for its outcrop around

Florissant, Colorado Florissant is an unincorporated town, a post office, and a census-designated place (CDP) located in and governed by Teller County, Colorado, United States. The CDP is a part of the Colorado Springs, CO Metropolitan Statistical Area. The Floriss ...

. The type specimen is currently preserved in the paleoentomological collections housed in the American Museum of Natural History in

New York City New York, often called New York City or NYC, is the most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the most densely populated major city in the Un ...

. ''H.''? ''protrita'' was first studied by Dr. Theodore D. A. Cockerell of the

University of Colorado The University of Colorado (CU) is a system of public universities in Colorado. It consists of four institutions: University of Colorado Boulder, University of Colorado Colorado Springs, University of Colorado Denver, and the University o ...

, with his 1922 type description being published in the journal ''American Museum Novitates''. Though Cockerell did not provide an explicit

explanation An explanation is a set of statements usually constructed to describe a set of facts which clarifies the causes, context, and consequences of those facts. It may establish rules or laws, and may clarify the existing rules or laws in relatio ...

for the specific epithet ''protrita''. The description of the specimen was delayed for five years due expectation that the description of the fossil would be completed by another researcher in 1910. However, after the description failed to be presented, Cockerell wrote the ''American Museum Novitates'' article rather than let the fossil continue to go undescribed. At the time of description, 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. Further refinement of the formation's dating has resulted in an age of 34 million years. This places the formation in the Eocene Priabonian stage.

Description

The holotype forewing of ''Hydriomena''? ''protrita'' is about in length with a outer margin, a lower margin and the color patterning faintly preserved. The wing has a checkered patterning in the fringe along the hind margin; the costal area is dark in coloration and broken by the antemedial band. Near the apical end of the costal cell is a distinct spot or pair of bars in a placement very similar to the antemedian mark of the modern species '' Hydriomena manzanita''. The basal area of the wing is pallid, and the subbasal line is faint. The admedial band is similar to that of ''H. manzanita'', but farther from the wing base and having a broader, less abrupt curvature. ''H.''? ''protrita'' was the first member of the family Geometridae to be described from the American fossil record. The placement of ''H.''? ''protrita'' is noted by Cockerell to be uncertain.

References

{{Taxonbar, from=Q5954553 † Fossil Lepidoptera Priabonian insects Fossil taxa described in 1922 Prehistoric insects of North America Florissant Formation