When I gave a talk on fossils last year at the Boerhaave Museum in Leiden, my Dutch friends told me to be sure to include a mention of the Maastricht mosasaur, the most famous fossil
in the Netherlands, even though I was actually talking about much more recent fossils such as mammoths. Maastricht, an ancient city on the Meuse River in the southeastern Netherlands, was a fortified crossroads of trade and nations for centuries, undergoing three sieges between the sixteenth and the eighteenth centuries. The Comte D’Artagnan, head of Louis XIV’s musketeers, was killed during the French king’s siege of Maastricht in 1673 (I mention this briefly in my book The Courtiers’ Anatomists).
Mosasaurs were large marine reptiles that flourished in the late Cretaceous period, between 100 million to 66 million years ago. The first fossil skull of a mosasaur, found near Maastricht in 1764, now resides in Teylers Museum in Haarlem. A second skull may or may not have been discovered by the surgeon Johann Leonard Hoffmann (1710-1782), whose name graces several prehistoric animals from the area, including mosasaurus hoffmanni, the biggest of the mosasaurs. The skull of this specimen is now at the Paris Museum of Natural History, part of the booty of the
Napoleonic Wars. The name “mosasaurus” means “Meuse lizard.”
The rich Maastricht fossil beds keep yielding more surprises. The most recent issue of Nature recounts the discovery and identification of “a new Mesozoic fossil that occupies a position close to the last common ancestor of Galloanserae.”(1) The group of prehistoric birds known as galloanserae (literally chicken-ducks) are the ancestors of all the birds we think of as poultry, including chickens, turkeys, ducks, and quail. Daniel Field from Cambridge University in the UK and his colleagues found a nearly complete skull as well as several bones of what Science magazine, reporting on this discovery, irreverently called a “turducken” and others called the “wonderchicken.” The turducken, of course, is a deboned chicken stuffed into a deboned duck, which is stuffed into a deboned turkey.
The origins of this concoction are shrouded in mystery.
The bones of the skull found in Maastricht incorporated characteristics of both modern
ducks and modern chickens and turkeys. Modern ducks, chickens, and turkeys branched off from the galloanserae over a period of several million years. Field and his colleagues believe that the fossil bird was about the size of a seagull. This press release from Cambridge University includes many pictures. They named it Asteriornis maastrichtensis, after the ancient Greek goddess Asteria. One of the Titans, Asteria changed herself into a quail and dove into the Aegean Sea to escape the pursuit of the lustful Zeus, who had taken the form of an eagle.
This discovery is important for several reasons. It predates the Cretaceous mass extinction during which all dinosaurs died, making it the oldest common fossil ancestor of modern birds. It gives information about what species actually survived the mass extinction, and how. In addition, it possibly shifts the origins of these birds from the south to the north; at the very least, it complicates recent genetic research on these origins.
(1) Daniel J. Field et al. ‘Late Cretaceous neornithine from Europe illuminates the origins of crown birds.’ Nature (19 March 2020). DOI: 10.1038/s41586-020-2096-0