Paleontologists have discovered a new species of Dromaeosaurus dinosaur from a nearly complete and unique skeleton found in Mongolia during the 2000s.
Reconstruction of Sri Lapax. Image credit: Connor Ashbridge / CC by 4.0.
This newly recognized dinosaur lived during the Campanian stage of the Cretaceous period, approximately 75 million years ago.
Based on various derived traits of the skull, vertebrae, and overall skeletal structure, this species can be classified within a group of bird-like theropods known as Dromaeosauridae.
It has been named Sri Lapax, marking it as the second species in this genus, following Sri Devi, which was identified in 2021.
“Dromaeosauridae represents a clade of small to medium-sized theropod dinosaurs that have been found in various Cretaceous deposits across North America, Asia, Europe, South America, and extending as far as Antarctica and Madagascar.”
“Remnants of feather-like structures, true pennaceous feathers, and gastrointestinal remains can be observed in well-preserved Dromaeosaurus specimens from the Lower Cretaceous period, such as Daurong Wanggi, Sinornithosaurus millenii, and Micro Raptor Zhaoianus.”
“Together with Troodontids, Dromaeosaurids are generally acknowledged as the closest modern relatives of birds.”
The nearly complete skeleton of Sri Lapax was discovered in the Djadochta Formation in Mongolia.
“This Dromaeosaurus specimen was illegally collected prior to 2010 and subsequently passed through private collections in Japan and the UK before being obtained by a French company,” noted paleontologist Eldonia.
“The precise location of the discovery remains unknown.”
“We plan to propose a tentative origin for it in the Mongolian Ukhaa Tolgod region based on documentation relating to the specimen.”
Holotype of Sri Lapax prior to preparations at the Royal Institute of Natural Sciences in Belgium in 2010. The arrows denote single femurs reconstructed using parts from both original femurs (which were separated during preparation). Image credit: Moutrille et al., doi: 10.1080/08912963.2025.2530148.
Sri Lapax exhibits a unique combination of vertebral and pelvic characteristics along with notably robust hands.
“One of the most distinctive features of Sri Lapax,” the researcher remarked.
“When adjusted for equal length, the phalangeal elements of the Pollex are about 150% more robust laterally compared to homologous elements in other Djadokhtan Dromaeosaurids, and these hands are stockier than those found in other known Dromaeosaurids.”
“We propose that frequent interactions with the Serratopsians, along with aggressive behaviors from those species, may have driven the development of more robust forelimbs and stockier hands in several Djadokhtan velociraptorines.”
“Assuming that Sri Lapax shared predatory habits with its close relative Velociraptor mongoliensis, the more robust construction of its hands suggests an adaptation for hunting larger and sturdier prey compared to typical Velociraptor diets.”
A study detailing this discovery was published online in the journal Historical Biology on July 13, 2025.
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Léa Moutrille et al. New bird-like dinosaurs from the Mongolian Upper Cretaceous period indicate niche diversification among belosirapthrins with particularly robust hands. Historical Biology published online on July 13th, 2025. doi:10.1080/08912963.2025.2530148
Source: www.sci.news
