Masillaraptor

Masillaraptor Temporal range: Middle Eocene
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Falconiformes
Genus:	Masillaraptor

Masillaraptor is an extinct genus of basal falconiform from the Middle Eocene, a long-legged relative of the living falcons. Classifying the Falconiformes is confusing, since Europe has placed the families into two orders (for more information see the Falconiformes page).

Known species

Currently only one species of Masillaraptor is known: M. parvunguis

Etymology

Masillaraptor comes from the Latin word masilla, which is the old name for the town of Messel, and a raptor is a bird of prey.

Parvungus is also Latin, coming from the word parvus which means small and feeble, while ungus means claw.

The name refers to the fact that the specimen's claws are small in comparison to those of other raptors.

Characteristics

The genus Masillaraptor is different from all other known avian taxa. It possesses a combination of characters that distinguishes it from all others.

1. The beak is almost as long as the cranium itself, with equal height over much of its length and a straight dorsal ridge. The beak curves just before its tip, restricting the nasal openings to the rear half of the beak.

2. The tibiotarsus is the longest bone in the leg.

3. On the second toe the first phalanx is shortened, whereas on the fourth toe the second and third phalanges are shortened.

4. The claws of Masillaraptor are small and weak compared to other falconiform birds with abbreviated pedal phalanges.

Characters (1) and (3) are derived within neornithine birds and also found in modern Accipitres, from which Masillaraptor is, however, distinguished in character (4).(Mayr, 2006.)

Differential

The Masillaraptor genus is different from all other genus of known birds, the beak, toe and phalanges are in different proportions along with other parts as well. These have been described by Mayr as follows:

–The Messelasturidae (Mayr 2005) (including Messelastur Peters 1994 and Tynskya Mayr 2000a) in, e.g.: beak proportionally much longer,and with straight culmen, tarsometatarsus proportionally longer, proximal phalanx of second toe shortened, middle phalanges of fourth toe proportionally shorter.

–The raptor-like, long-legged early Eocene Neocathartes Wetmore 1950 (which actually is a member of the Cariamae, see Wetmore 1944, 1950; Olson 1985) and all phorusrhacoid birds in: carpometacarpus with narrower spatium intermetacarpale and straight os metacarpale minus, proximal phalanx of second toe shortened.

–The superficially raptor-like early Eocene ForoOlson 1992 in: beak longer, carpometacarpus with narrower spatium intermetacarpale and straight os metacarpale minus, proximal phalanx of second toe and second and third phalanges of fourth toe shortened. </(Mayr, 2006)>

Fossil Specimens

There are two specimens of Masillaraptor. Only one specimen was referenced for classification because the other is housed in an unknown private collection. Both specimens are a slab of rock containing a neary complete, articulate but poorly preserved skeleton. The specimens are both believed to be adult members of the species. Both specimens were discovered in the Messel pit, an old shale mine known for the extremely well preserved fossils that have been discovered there. It is hoped that more specimens will be discovered and more will be learned about these prehistoric birds.

References

• A new raptorial bird from the Middle Eocene of Messel, Germany, Mayr 2006
• dinoweb
• The Raptor Center
• Falconiformes
• Messel fossil bird
• Explore Birds of Prey