This week we will be taking a look at a unusual theropod. Check out Mexidracon longimanus!
Mexidracon was a theropod dinosaur that lived in what is now Coahuila, Mexico, during the late Cretaceous period, about 72 million years ago. From beak to tail it measured about 10 feet (3m) long. Its genus name translates to "Mexican Dragon" and its species name to "long hand". It may have been a plant-eater when alive or possibly eaten a mix of both plants and meat.
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| Mexidracon life reconstruction in watercolor by Christopher DiPiazza. This dinosaur may have been an omnivore, using its long hands to reach narrow places where prey might hide. |
Mexidracon was a member of the ornithomimid family of dinosaurs, famous for resembling modern ostriches as a result of convergent evolution. They had long necks with beaks with the later surviving forms lacking teeth. The skull of Mexidracon was never found so it is difficult to know for sure if this was the case for it, but given its presence in the late Cretaceous and its close relationship to relatives we know were toothless, like Struthiomimus, it may have been as well. Mexidracon is noted to have slightly shorter, more robust lower leg bones than other ornithomimids, but it was still likely a fast runner in life.
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| Photograph of some of Mexidracon's bones with labels (in Spanish) (photo credit: Global Revista) |
The most notable and unique feature about Mexidracon, however, is its hands. The hand bones, called metacarpals (bones that make up our palms), were extremely long, which is where it earned its species name from. It then also had three average length for an ornithomimid (but still relatively long) fingers, each tipped with a claw on each hand. It is a total mystery why this dinosaur would evolve such an odd trait but there are a few ideas. The first is the hands may have helped it get food, perhaps gathering vegetation or reaching into crevices or burrows of small creatures, more effectively. The other possibility is the elongated hands may have been part of a display for members of the same species. We know ornithomimids had feathers, so perhaps there were fancy display feathers growing there to impress mates or intimidate rivals? We may never know.
Mexidracon came from a habitat that paleontologists are still very much actively investigating and finding new exciting specimens from right now. Other dinosaurs that have been found in the same area of Mexico include the hadrosaur, Velafrons, and the ceratopsian, Coahuilaceratops.
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