In the last few days of 2025, a bizarre new dinosaur taxon was scientifically described. Researchers have published a paper about a fragmentary skeleton from the Upper Cretaceous (Maastrichtian) Nemegt Formation at Khermeen Tsav in the Gobi Desert of Mongolia. Named Manipulonyx reshetovi, it has been assigned to the Parvicursorinae subfamily of the Alvarezsauridae. The specimen includes an articulated and complete forelimb and crucially much of the manus (hand). The single, large digit (digit I) is preserved. However, evidence of rudimentary side fingers and a complete series of proximal carpal bones are also preserved. This is the first time that proximal carpal bones have been identified in a parvicursorine.
A life reconstruction of Manipulonyx reshetovi. Note the scale bar equals 10 cm. Picture credit: Tim Bollinger (TotalDino) with additional annotation by Everything Dinosaur.
Picture credit: Tim Bollinger (TotalDino) with additional annotation by Everything Dinosaur.
Our thanks to the artist Tim Bollinger for giving us permission to use his illustration of this recently described theropod. Tim’s website is a great resource with lots of amazing dinosaur images, updates and helpful information about the Dinosauria: Visit Total Dino.
Manipulonyx reshetovi
With the description of this new parvicursorine, palaeontologists have a much better understanding of the hand anatomy of this type of dinosaur. In addition, they have hypothesised that parvicursorines specialised in eating eggs. Therefore, the short forelimbs ended in highly specialised appendages that permitted these little theropods to hold and puncture the eggs of other dinosaurs.
The fossilised material consists of a pair of cervical vertebrae, one dorsal vertebra, sacral vertebrae and caudals. Moreover, the field team recovered fragmentary bones representing hindlimbs and part of the pelvic girdle. In contrast to the scrappy nature of this material, most of the bones from both forelimbs were found. The carpal bones indicate the presence of unique spikes on the wrist that would have helped this dinosaur to grasp and manipulate eggs. The enlarged claw on the powerful first digit is thought to have been used to puncture eggs so that the contents could be consumed.
Previous discoveries have suggested that parvicursorines could have been specialised insectivores. It had been proposed that their specialised hands had evolved to help them dig for insects or for breaking into termite mounds. For example, in 2022 we wrote an article about Dzharaonyx eski from Uzbekistan.
To read Everything Dinosaur’s blog post: The Remarkable “Old Dzharakuduk Claw”.
Were Some Alvarezsaurids Ovivores?
Alvarezsaurids are an unusual group of maniraptoran theropods. They evolved long hind limbs, compact bodies, and extremely reduced forearms. However, these arms were not useless. Instead, they supported a powerful, specialised manus. In most species, the hand appears adapted for a single dominant claw. This unusual body plan sets alvarezsaurids apart from all other theropods.
Within this family, Manipulonyx reshetovi belongs to the subfamily Parvicursorinae. These dinosaurs are typically lightly built and highly cursorial. Moreover, they show extreme forelimb modification. However, Manipulonyx goes much further. Its forelimbs preserve the wrist, metacarpals, and digits in near-complete condition. Notably, the manus shows reinforced elements and distinctive bony spikes. Therefore, researchers can assess how the hand functioned in life, not just how it looked.
The scientists writing in the Proceedings of the Zoological Institute of the Russian Academy of Sciences speculate that M. reshetovi was an egg-eater (ovivore). This hypothesis builds on earlier discussions about alvarezsaurid diets. For example, back in 2018 we authored an article about Qiupanykus zhangi, an alvarezsaurid from central China. At the time, it was speculated that Qiupanykus was an ovivore.
To read the blog post on Q. zhangi: Did Alvarezsaurids Eat Eggs?
Mike from Everything Dinosaur commented:
“Manipulonyx reshetovi provides a rare and valuable window into parvicursorine evolution. Above all, its well-preserved forelimbs transform how we interpret alvarezsaurid behaviour and feeding strategies. The forelimb is the most completely known of any parvicursorine and its discovery highlights the incredible diversity of the Dinosauria.”
The scientific paper is published in Proceedings of the Zoological Institute of the Russian Academy of Sciences.
The award-winning Everything Dinosaur website: Prehistoric Animal and Dinosaur Models.
Leave A Comment