Known from a single specimen discovered in Spain back in 1993 Pelecanimimus (P. polyodon) from the Las Hoyas lagerstätte was the first unambiguous ornithomimosaur described from Europe. Although the scientific paper erecting the genus was published in 1994, no detailed examination of the holotype fossil material (LH 7777) had been undertaken.

A re-examination of the holotype fossil has been carried out by a team of international scientists, which included Francisco Ortega, one of the authors of the original scientific paper describing this 2-metre-long theropod. They conclude that Pelecanimimus was remarkably bird-like although as a member of the Ornithomimosauria it was not that closely related to the dinosaur lineage that led to the evolution of the birds.

An Ossified Sternum

Pelecanimimus when it was named, was the only ornithomimosaur that had a preserved ossified sternum. The sternum is not usually preserved in theropods, it has been suggested that this part of the skeleton was not ossified and therefore it did not fossilise well, or perhaps the absence of this structure was due to preservational bias. The distance observed between the coracoids in articulated theropod specimens led to many palaeontologists inferring its presence. In this new paper, the researchers examined the shape of the sternum and concluded that its morphology was similar to the sternums of dinosaurs more closely related to birds such as Velociraptor and Oviraptor (the Maniraptora clade).

Pelecanimimus Breathed Like a Bird

Furthermore, the research team found evidence of the presence of uncinate processes. These small, hook-shaped bones are linked to the ribs and are also present in extant and extinct birds. Pelecanimimus is the only known representative of the Ornithomimosauria with these structures and this is the first time that uncinate processes have been found in a non-maniraptoran theropod. If maniraptorans evolved these structures, along with the distantly related Pelecanimimus, this suggests convergent evolution.

In birds, uncinate processes function to increase the mechanical advantage for movements of the ribs and sternum during respiration. They make breathing more efficient. In summary, the research team suggest Pelecanimimus, breathed like a modern bird.

Elena Cuesta, the lead author of the study from the Fukui Prefectural University, Japan explained:

“The fact that Pelecanimimus preserved these processes suggests that it also had a bird-like breathing mechanism. Apparently, the origin of such avian-like features is older and more widespread than thought. However, the evolutionary history of both the ossified sternum and uncinate processes is still unclear. Nevertheless, their detection in Pelecanimimus confirms that these elements were present in Ornithomimosauria as well as in other dinosaurs.”

Distinctive Features on the Hands

The joint Japanese/Spanish research team also discovered distinctive features on the hands. The manus of Pelecanimimus has conspicuously elongated metacarpals, particularly metacarpal I and lengthened distal phalanges, a feature also found in some later, more derived ornithomimosaur species. The authors of the study conclude that these anatomical features require the erection of a new clade, the Macrocheiriformes. This clade is defined as including Pelecanimimus and more derived ornithomimosaurs. The term Macrocheiriformes, means “forms with large hands.”

The scientific paper: “Pelecanimimus (Theropoda: Ornithomimosauria) postcranial anatomy and the evolution of the specialized manus in Ornithomimosaurs and sternum in maniraptoriforms” by Elena Cuesta, Daniel Vidal, Francisco Ortega, Masateru Shibata and José L Sanz published in the Zoological Journal of the Linnean Society.

A new dinosaur from Appalachia – Parrosaurus missouriensis.

For much of the Cretaceous the North American landmass was effectively divided into two, by a shallow sea (Western Interior Seaway). At its greatest extent it was around 1,000 kilometres (600 miles) wide, the long, narrow landmass that represented the western part of North America is known as Laramidia and palaeontologists have amassed a huge amount of data about the abundant dinosaurs that roamed these ancient shores. The eastern landmass, Appalachia, stretched from Newfoundland in the north, to the mid-west American states, but in comparison little is known about the Appalachian dinosaur fauna.

A new species of duck-billed dinosaur has been added to the Appalachian biota, named Parrosaurus missouriensis and as the species epithet suggests, this Late Cretaceous herbivore was found in Missouri.

Very Rare Dinosaur Discovery

In contrast to the extensive, rapidly eroding “Badlands” of Montana, Wyoming and North/South Dakota, rocks of Cretaceous age from the ancient landmass of Appalachia are not exposed to any great extent in eastern North America. Dinosaur fossil bearing units are not being eroded, they remain buried under other strata and to add to this dilemma, much of the eastern part of the USA is conurbation. However, there are bright spots for palaeontologists looking for dinosaur bones.

Mines, eroding rivers and construction sites can all provide opportunities for fossil discoveries. Indeed, it was the digging of a well near to the village of Glen Allen in Bollinger County, south-eastern Missouri back in 1942 that led to the finding of several dinosaur bones, the first time such fossils had been reported from the “Show Me State”.

The caudal vertebrae that were excavated from the site were thought to represent a sauropod and it was scientifically described and named Neosaurus missouriensis in 1945 (Gilmore and Stewart). It was noted that the genus name was already occupied, Neosaurus having been erected in 1869 for a Palaeozoic synapsid from France, so the scientific name was changed to Parrosaurus missouriensis.

Duck-billed Dinosaur Fossils

Ironically, duck-billed dinosaur fossils had been found in North Carolina and the species Hypsibema crassicauda was erected in 1869, a review of the Glen Allen material (Baird and Horner), led to the erection of the species Hypsibema missouriensis as the Missouri fossils were confirmed to be hadrosaurid and showed similarities with the fossils that had been found in North Carolina.

More recent excavations carried out at the Glen Allen site, led by fossil expert Guy Darrough and with the support of the Field Museum of Chicago has led to the discovery of at least four individual hadrosaur specimens. The fossils found in close association in black clay represent three adults and juvenile.

The site has yielded other fascinating fossils, providing a glimpse into the fauna of Appalachia. For example, a scute (dermal armour) from a giant crocodilian has been found, fossils of turtles discovered and even the tooth of a tyrannosaur has been uncovered.

Parrosaurus missouriensis

The extensive fossil material found as led to the establishment of a new species Parrosaurus missouriensis. This very notable fossil location might just prove to be a headache for the State administration, as in 2004 these fossils had been declared Missouri’s official State dinosaur when they were assigned to Hypsibema missouriensis.

The story has been widely reported and team members at Everything Dinosaur are optimistic that once the fossil material has been studied in detail and more of the specimens cleaned and prepared, then new discoveries will be made.