Haplocheirus is labeled as a transitional fossil but why? Well according to science daily, “it shows an early evolutionary step in how the bizarre hands of later alvarezsaurs evolved from earlier predatory dinosaurs.” A typical metaphysical statement not a science one, then the BBC had it’s take on it, declaring it solving the mystery between dinosaur and bird evolution!
This is hype and misleading journalism in a desperate attempt to convince the public at large to conceptualize dinosaurs turning into birds. The original paper says little about evolution, in fact Richard Stone and “feathered-dinosaur” hunter Xing Xu say the fossil does not solve anything but rather confuses the alleged dinosaur-to-bird transition.
Xu suggests that the fossil demonstrated the basal Maniraptorans which were not secondarily flightless birds and then he uses metaphysical reasoning claiming it convergently evolved!
“Haplocheirus is the largest alvarezsauroid known from complete material (see SOM), and its basal phylogenetic position suggests a pattern of miniaturization for the Alvarezsauroidea, relatively rare in dinosaurs but convergently evolved in Paraves.”
“Derived alvarezsauroids have a simplified, homogeneous dentition convergent with that of some extant insectivorous mammals, but Haplocheirus has recurved, serrated teeth and caniniforms that suggest carnivory was the primitive condition for the clade.”
“The presence in Haplocheirus of only slightly reduced second and third manual digits and curved unguals with flexor tubercles on these digits implies that the hand was fully functional and Haplocheirus retained some grasping ability, unlike the presumably limited function of the greatly reduced lateral manual elements of Mononykus and Shuvuuia.”
The mediolaterally narrow McIII (metacarpal three) and the greatly shortened and slender McIV suggest that the extensive digital reduction and fusion seen in derived alvarezsauroids was already under way by the earliest Late Jurassic, proceeded from lateral to medial on the manus and, surprisingly, initially involved reduction in length of only McIV.”
There is no mention of a dinosaur evolving into a bird here as the media like science daily and the BBC have claimed. What they did find was a unique dinosaur with fully functioning arms and grasping claws. Convergent evolution is just being used to fix the data into the framework in which they believe it to be rather than allowing the evidence to lead them!