Zhongjianosaurus: a tiny dromaeosaurid? No.

Wikipedia reports,
“Zhongjianosaurus yang (Xu and Qin 2017, Yixian Fm. ~60 cm in ln length; ) is a genus of dromaeosaurid belonging to the Microraptoria.”

Unfortunately
the large reptile tree (LRT) nested Zhongjianosaurus with the scansoriopterygid bird, Mei long (Fig. 1). Neither does Microraptor nest with dromaeosaurids. It nests closer to Ornitholestes. Increasing the taxon list will resolve this issue for other workers as it did here.

Figure 1. Zhongjianosaurus compared to Mei long, a scansoriopterygid bird.

Figure 1. Zhongjianosaurus compared to Mei long, a scansoriopterygid bird. Both have relatively short forelimbs vs. long hind limbs among other traits.

Xu and Qin report,
The distal carpal is represented by the compound ‘semilunate’ carpal, formed by the addition of distal carpal 4 on its ventrolateral corner, and this morphology also is present in the troodontid Mei long (Xu et al., 2014a).”

Well, 
Mei long is indeed a troodontid, but so are all birds. Better to label it a scansoriopterygid bird to avoid confusion.

When you read the PDF, bear in mind
that the authors do not label the manual digits 1–3, but 2–4 as they pay homage to Limusaurus with what I call digit 0.

Perhaps if the pelvis or skull was preserved
in Zhongjianosaurus it would nest elsewhere. At present shifting Zhongjianosaurus to Microraptor adds 6 steps. Shifting Zhongjianosaurus to Velociraptor adds 9 steps. With the given data set and character list, this is how it all shakes out at present. And, you have to admit, it’s a pretty good match!

References
Xu X; Qin Z-C 2017. A new tiny dromaeosaurid dinosaur from the Lower Cretaceous Jehol Group of western Liaoning and niche differentiation among the Jehol dromaeosaurids” (PDF). Vertebrata PalAsiatica. In press.

wiki/Zhongjianosaurus

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2 thoughts on “Zhongjianosaurus: a tiny dromaeosaurid? No.

  1. Your interpretation of the hand of Mei is very, very strange, and what have you done to the ilium?

    Increasing the taxon list will resolve this issue for other workers as it did here.

    Increasing the character list just might resolve this issue for you as it did for other workers. :-)

  2. re: Mei – I report my findings, some strange, others commonplace. The ilium is not well exposed as I recall. What is exposed is shown here.
    re: Increasing the character list just might resolve this issue for you as it did for other workers. :-) – You’re guessing. And you might be right. But as I say that, I’m guessing too. Bottom line: The present character list has proven to be sufficient to lump and separate all included taxa. The other bottom line: you don’t like the results when they come from me. But you do like the results that others produce, like the close relationship of parasuchians and pterosaurs without intervening taxa that others recover. Take care, Dave.

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