Palaeohierax gervaisii
By Scott Reid
Etymology: Old Hawk
First Described By: Milne-Edwards, 1863
Classification: Dinosauromorpha, Dinosauriformes, Dracohors, Dinosauria, Saurischia, Eusaurischia, Theropoda, Neotheropoda, Averostra, Tetanurae, Orionides, Avetheropoda, Coelurosauria, Tyrannoraptora, Maniraptoromorpha, Maniraptoriformes, Maniraptora, Pennaraptora, Paraves, Eumaniraptora, Averaptora, Avialae, Euavialae, Avebrevicauda, Pygostaylia, Ornithothoraces, Euornithes, Ornithuromorpha, Ornithurae, Neornithes, Neognathae, Neoaves, Inopinaves, Telluraves, Afroaves, Accipitrimorphae, Accipitriformes, Accipitridae
Status: Extinct
Time and Place: Sometime between 27 and 22 million years ago, from the Chattian of the Oligocene through the Aquitanian of the Miocene.
Palaeohierax is known from near Chaptuzat, in the Auvergne-Rhône-Alpes of France
Physical Description: Palaeohierax is one of many fossil birds known from mainly toe bones, but surprisingly, this toe bone is well preserved and tells us a decent amount about this dinosaur. This toe clearly marks Palaeohierax as a raptor, probably a daytime one; it is wider and flatter than those of hawks, and more robust than hawks as well, linking it in most likely to Ospreys or Eagles. It is also very similar to the living Palm-Nut Vulture, so it’s difficult to place it exactly within the Accipitrids. It has a less broad outer surface than Eagles, and does have a little bit of an enlarged barrel to the toe as in the Palm-Nut Vulture. However, it has small portions to the bone and strong edges, much like eagles. A part of a leg bone and hand bone have been found as well, but they are more fragmentary than the toe bone.
So, in short, Palaeohierax would have resembled a cross between hawks and the Palm-Nut Vulture - sort of a catch-all Accipitrid, but robust as well. This means it may have actually resembled the Bearded Vulture in appearance. It would have been about the same size as the modern White-Tailed Eagle, which has a typical wingspan of up to 2.45 meters - making Palaeohierax on the larger side for birds of prey.
Diet: As a large, robust bird of prey, Palaeohierax would have mainly fed upon other animals such as mammals, reptiles, and birds.
By José Carlos Corteés
Behavior: Palaeohierax would have probably resembled living birds of prey in its behavior, spending much of its day flying around and searching for prey; it would have dived down upon spotting them and used its large talons to grab onto its food (which would have been especially robust and muscular). It’s possible it would have also eaten carrion, given its similarities to some vultures; but it’s uncertain if that would have made up the bulk of its diet, especially given how its toes seem well adapted for hunting prey. As a dinosaur, it would have most likely taken care of its young, but more specifics on its breeding behavior are unknown.
Ecosystem: Palaeohierax probably lived alongside the shoreline of France at the time, given what sorts of other animals have been found in the same time and region. That being said, the exact fossil location of Palaeohierax has not been well reported. This was a fairly lush coastal environment, with a variety of pine trees, as well as many kinds of algae.
Here, there were many kinds of animals that Palaeohierax would have been able to feed upon - different turtles such as Ergilemys and Ptychogaster; lizards like Pseudeumeces, Dracaenosaurus, and Ophisauromimus; many kinds of rodents, shrews, a horse-like rhino relative called Allacerops, true rhinoceroses by the names of Molassitherium and Ronzotherium, and some early cats like Proailurus that would have probably attempted to hunt Palaeohierax in return. There was also a large, bulky hoofed mammal called Paenanthracotherium. As for other dinosaurs, they weren’t quite as commonly fossilized; but the gannet Empheresula was present in the same general time and place.
Other: Palaeohierax, despite its mysterious taxonomic placement within the birds of prey, is one of the few vulture-like dinosaurs known from the Neogene of Europe; and one of only a handful of Accipitrids from this time and place overall.
~ By Meig Dickson
Sources under the Cut