A block containing the partial skeleton of Linhevenator. Abbreviations: ds, dorsal vertebrae; lf, left femur; li, left ischium; lpe, left foot; rh, right humerus; rs, right scapula; sk, skull. From Xu et al., 2011.
What makes Linehvenator particularly unusual are some of the details of its limbs. Compared to other troodontids, Linhevenator had a relatively long shoulder blade, a relatively short and thick humerus, and its second toe was tipped in a specialized, retractable claw like that seen in Troodon but not in some earlier members of the group. This is a curious suite of characteristics. Whereas Linhevenator appears to have had a killing claw similar to that of its dromaeosaurid cousins like Deinonychus, the newly described dinosaur may have had proportionally short and strongly muscled arms. This may hint that Linhevenator was not using its arms to capture prey in the same way as dromaeosaurids or earlier troodontid dinosaurs, even if it did have a specialized killing claw. Instead, Xu and co-authors argue that the dinosaur may have had arms adapted to digging, climbing, or something else entirely, although testing these hypotheses is difficult at present. With any luck, additional discoveries of troodontids will help flesh out what these peculiar dinosaurs were like in life.
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