Masillaraptoridae is an extinct family of

stem-group In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. ...

falconiform The falcons and caracaras are around 65 species of diurnal birds of prey that make up the family Falconidae (representing all extant species in the order Falconiformes). The family likely originated in South America during the Paleocene and is d ...

birds from the

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

of Europe. They are noted for their relatively long legs. Two genera have been named: ''

Danielsraptor ''Danielsraptor'' (meaning "Michael Daniels's thief") is an extinct genus of masillaraptorid bird from the Ypresian, Early Eocene (Ypresian) Walton Member of the London Clay Formation in Essex, United Kingdom. The genus contains a single species ...

'', from the

London Clay The London Clay Formation is a Sediment#Shores and shallow seas, marine formation (geology), geological formation of Ypresian (early Eocene Epoch, c. 54-50 million years ago) age which outcrop, crops out in the southeast of England. The London C ...

of England, and ''

Masillaraptor ''Masillaraptor'' is an extinct genus of masillaraptorid, a group of primitive falconiforms, from the Middle Eocene Messel Pit, Germany. It is a long-legged relative of the living falcons. Known species Only one species of ''Masillaraptor'' ...

'', from

Messel Pit The Messel Formation is a Formation (geology), geologic formation in Hesse, central Germany, dating back to the Eocene Epoch (geology), epoch (about 47 Ma). Its geographic range is restricted to the Messel pit. There it unconformably overlie ...

in Germany.

Description

Masillaraptorids had long legs, which may indicate that they had a

terrestrial Terrestrial refers to things related to land or the planet Earth, as opposed to extraterrestrial. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on o ...

lifestyle, foraging on the ground similar to modern caracaras. They had large

pygostyle Pygostyle is a skeletal condition in which the final few caudal vertebrae are fused into a single ossification, supporting the tail feathers and musculature. In modern birds, the rectrices attach to these. The pygostyle is the main component o ...

s, suggesting that they would have likely had long tail feathers. This, in addition to their long

ulna The ulna or ulnar bone (: ulnae or ulnas) is a long bone in the forearm stretching from the elbow to the wrist. It is on the same side of the forearm as the little finger, running parallel to the Radius (bone), radius, the forearm's other long ...

e, suggest that they were capable of well-developed flight. Their beaks are similar to those of extinct

phorusrhacids Phorusrhacids, colloquially known as terror birds, are an extinct family of large carnivorous, mostly flightless birds that were among the largest apex predators in South America during the Cenozoic era. Their definitive fossil records range from ...

and extant caracaras.

Classification

The

cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...

below displays the

phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

position of Masillaraptoridae within the Falconiformes:

References

{{Taxonbar, from=Q113124861 Falconiformes Prehistoric bird families