A newly identified dinosaur, Migmanychion laiyang, has been described from fossils found in Inner Mongolia, China.
Living 121 million years ago during the Early Cretaceous, the dinosaur belongs to a group known as maniraptorans which includes the lineage that survived to today as birds.
This group is part of the broader therapods – a clade which includes Allosaurus and Tyrannosaurus rex.
Maniraptorans are characterised by long arms, three-fingered hands and a half-moon shaped bone in their wrists. It is the only group known to include flying dinosaurs. But, just when flight evolved among maniraptoran dinosaurs continues to be subject to debate.
Migmanychion has “a peculiar combination of features in the hand” according to the paper describing the animal published in the journal Cretaceous Research.
The dinosaur’s hands were similar to those of therizinosauroids and oviraptorosaurs in some ways. The most famous example of therizinosauroids is Therizinosaurus – a five-tonne, pot-bellied dinosaur with the largest known claws of any animal ever, reaching longer than 50 centimetres. Oviraptors are feathered dinosaurs with short, beaked, parrot-like skulls and an omnivorous diet.
But Migmanychion most closely resembles its nearby neighbour Fukuivenator paradoxus (pictured above), discovered in Japan and first described in 2016.
Migmanychion is known from an incomplete skeleton found at the Pigeon Hill locality of the Longjiang Formation near Baoshan town in Inner Mongolia. Among the bones are fragments of ribs, the end of one forearm, and a complete hand.
“Although based on a fragmentary specimen, the holotype of Migmanychion laiyang shows a peculiar hand morphology different from all known theropods, supporting the erection of a new taxon,” the authors write.
The weirdly proportioned phalanxes (finger bones) of Migmanychion are features only shared with Fukuivenator. The researchers conclude that their bizarre features suggest that these dinosaurs probably evolved separately from the lineage that led to modern day birds.
They hope to find more Migmanychion laiyang specimens to more accurately place it in the maniraptoran evolutionary tree.