Foro panarium

By Ripley Cook

Etymology: Breadbasket’s Hole 

First Described By: Olson, 1992 

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, Columbaves, Otidimorphae, Musophagiformes

Status: Extinct 

Time and Place: Between 53.5 and 48.5 million years ago, in the Ypresian of the Eocene 

Foro is known from the Fossil Butte Member of the Green River Formation of Wyoming 

Physical Description: Foro had a downward sloping, distinctive skull, with a slight point to the tip at the end of the beak, hanging off of a long neck. It had a large, rounded head, a fairly stout body, and long spindly legs. Its wings were decently sized too, making this in general a very lanky sort of bird. However, these wings were probably weak, and in addition to the stocky body it wouldn’t have been the world’s greatest flier. As for its general size, it was probably about the size of a modern roadrunner, reaching between 22 and 24 centimeters in length; it was probably similar in many ways to living roadrunners, while simultaneously being like a bustard, a hoatzin, and a relative of the modern day turacos. Evolution is wild, man. 

Diet: Given it had the general head-shape of a Hoatzin, it seems at least somewhat likely that Foro was herbivorous, though this was of course evolved convergently to the Hoatzin (as Foro was probably a stem-turaco). This is further corroborated by the fact that turacos are also mostly herbivorous. 

Behavior: Foro was a ground-dwelling bird, rather than tree-dwelling like modern turacos; it would use its long legs to wander about its lake environment, searching for food to eat and moving through more difficult ground material such as mud and dirt. In this way it was much more like a living bustard than a living turaco, indicating the bustard way of life was actually the ancestral case for cuckoos and turacos before they adapted for their unique arboreal roles. As a weird cross between a bustard and a wading bird, it would have spent a good amount of time moving about the ground, grabbing food from the mud and in the low-lying plants, and running away rapidly at the first sign of danger. It was still able to fly, and would use that when the danger was way too close. As a bird, it would have been an active animal; it is especially uncertain whether or not it was particularly social, but it probably took care of its young. 

By Scott Reid

Ecosystem: The Green River Formation is a famous environment from the early Eocene of North America, showcasing the burst of creatures after the end-Cretaceous extinction that came forward as the global rainforest reached its peak, and serving as a host of creatures that were precursors to modern forms. This was a fossil lake system scattered across the jungle in loosely dense vegetation, including sycamore trees and ferns, palms, and many other kinds of plants. As the Rocky Mountains formed nearby, nutrients would randomly spike in the lake, dumping phosphorus and suffocating the fish inside. This lead to unique preservation and an amazing number of fossils from Green River. Here there were a variety of rays, catfish, herrings, and countless other fish; crocodilians like Borealosuchus; early primates, bats, and an armadillo-esque mammal. Birds were also extremely common: there was the gull-like frigatebird Limnofregata, the Lithornithids Pseudocrypturus and Calciavis, the flamingo-duck Presbyornis, the pre-pheasant Gallinuloides, the early swift-hummingbird Eocypselus, the frogmouth-esque Fluvioviridavis and Prefica, the mousebird Anneavis, the woodpecker Neanis, the Parrots of Prey Cyrilavis and Tynskya, and the parrot-footed passerines Zygodactylus and Eozygodactylus. In this way, Foro was a notable and usual member of the ecosystem, showcasing the weird mode of evolution of the modern Turaco group. 

Other: Foro has been the subject of a fascinating research history, with it originally being called its own thing in the Cuckoos, and then thought to be a Hoatzin for a while, and then finally assigned as a stem-turaco. This is of utter importance because it showcases how neotropical birds like the turacos (which, today, are limited to Africa) were once widespread – this also applies to many other groups of birds, and this collapse of tropical birds in North America and Europe is an object of intense study. As the Global rainforest collapsed, the evolutionary trajectory of modern birds changed dramatically, and Foro was a part of that. On the other hand, Foro and other birds known from the Paleocene and Eocene epochs showcase how dinosaurs managed to bounce back from the extinction; birds were more ground-dwelling than tree-dwelling at first, given the lack of trees in impact winter; Foro was a ground-dwelling bird, but one on the path to tree-life, much like many other dinosaurs in this early part of the new era. 

~ By Meig Dickson

Sources under the Cut