After doing some extra reading on Troodontids and mainly the paper describing Sinornithoides, there is a short mentioning of an unnamed Troodontid specimen named GIN 100/44 that was described by Barsbold in 1987 which is the indeterminate Troodontid in The Dinosauria pictured on page 263.
The reference is: Barsbold, R., Osmólska, H., and Kurzanov, S.M. 1987. On a new troodontid (Dinosauria, Theropoda) from the Early Cretaceous of Mongolia. Acta Paleontologica Polonica, 32: 121-132
For those interested, but there is no further mentioning of this animal anywhere, except for the few pictures available in The Dinosauria. These comprimise a right manus and metacarpus and the left pes and left metatarsus. The material, at least as far as the text mentions it, comprimises: a quadrate, partial dentary and poorly preserved postdentary section, a partial basioccipital, a poorly preserved series of 5 cervicals, a semilunate carpal, the complete metacarpus, several phalanges and unguals, fragments from the pelvis and a partial left foot. Maybe more elements were discovered, but these are the elements mentioned.
At a first glance at the age, I thought the material could be assigned to a specimen of Sinornithoides (Currie, P.J., Zhiming, D. 2001), but as a I started to look at details, some differences appeared. The most eye-catching one is the major difference in metatarsal morphology: in GIN 100/44 the overall appearance is clearly more robust than is in Sinornithoides, as is in the distal elements of the metatarsals. Another thing regarding the metatarsus, in the unnamed Troodontid shows a distinctly less compressed distal metatarsal III than this is the case in Sinornithoides. Metatarsal I is placed more to the end in Sinornithoides compared to GIN 100/44. Unfortunately the paper describing Sinornithoides doesn't show the metatarsus in extensor view, so no further comments can be made regarding this elements. Pedal digit II 2 is also relatively longer in Sinornithoides, which is a primitive character in the Troodontid family according to the Dinosauria. The manus is uncomparable between the two, because the distal metacarpals are not illustrated in the Sinornithoides paper.
The relationships that are discussed in the Sinornithoides-paper available for GIN 100/44 state that this unnamed genus seems to be the sister taxon to Sinornithoides which is again a sister taxon to genera such as Byronosaurus, Troodon and Saurornithoides, which results in:
`- +Sinornithoides youngi
According to the text the preserved basioccipital portion of the braincase in specimen GIN 100/44 had not developed the lateral depression, or at least it still lacked the basioccipital portion of that depression.
But my question is: what is it? Has it been more thourougly described recently and does someone have any additional pictures of this specimen that I could have? And what other info is available for the specimen?
Thanks in advance!