Open Paleo

Sinovenatorinae

Shen et al., 2017 Type genus Sinovenator

Its genera lived 125.8–121.4 million years ago Early Cretaceous
Early Cretaceous stages

Sinovenatorinae is a subfamily of small, basal troodontids from the Early Cretaceous Jehol Biota of China, grouping Sinovenator with Mei. Its erecting analysis also included Sinusonasus and Daliansaurus (Shen and colleagues, 2017), and some analyses add Jianianhualong, but later analyses often place these three outside the subfamily. Its members are among the smallest and most basal of the troodontids, the bird-like, gracile theropods known for their large braincases and long, slender legs built for fast running. Members of the group share a distinctively wide, flattened fourth metatarsal. The clade's exact composition and internal relationships remain debated, with some analyses instead recovering these Chinese taxa as a graded succession of lineages rather than a single well-defined clade.

Under dispute

The monophyly and composition of Sinovenatorinae are contested. It was erected by Shen and colleagues (2017) for the Early Cretaceous Chinese troodontids Sinovenator, Mei, Sinusonasus and Daliansaurus. Hartman and colleagues (2019) also recover a clade of that name among the first-branching troodontids, but with a different membership — excluding Sinusonasus and Daliansaurus, which they place closer to Hesperornithoides, and including Xiaotingia and Jianianhualong instead. Yin and colleagues (2018) recover Mei, Sinovenator and Sinusonasus as successive early-branching troodontids rather than as a clade, and Jones (2026) notes that studies "seldom agree on the clade's membership." It is retained in its original sense.

Diagnosis

  1. Small body size with a proportionally large braincase
  2. Anterior dentary teeth more closely packed than posterior teeth
  3. Metatarsal IV mediolaterally wide

Genera placed directly in Sinovenatorinae

  • Mei Xu & Norell, 2004 Barremian (125.8–121.4 Ma)China
  • Sinovenator Xu et al., 2002 Barremian (125.8–121.4 Ma)China

References

  1. Shen, C.; Lü, J.; Liu, S.; Kundrát, M.; Brusatte, S. L.; Gao, H. (2017). A New Troodontid Dinosaur from the Lower Cretaceous Yixian Formation of Liaoning Province, China. Acta Geologica Sinica (English Edition) 91(3): 763-780. Wiley. doi:10.1111/1755-6724.13307

    Erected Sinovenatorinae with a stem-based definition, recovering Sinovenator, Mei, Sinusonasus and Daliansaurus within it.

    shen2017b
  2. Hartman, S.; Mortimer, M.; Wahl, W. R.; Lomax, D. R.; Lippincott, J.; Lovelace, D. M. (2019). A new paravian dinosaur from the Late Jurassic of North America supports a late acquisition of avian flight. PeerJ 7: e7247. PeerJ. doi:10.7717/peerj.7247

    Recovered Sinovenatorinae with a different membership, excluding Sinusonasus and Daliansaurus and including Xiaotingia and Jianianhualong.

    hartman2019a
  3. Yin, Y.; Pei, R.; Zhou, C. (2018). Cranial morphology of Sinovenator changii (Theropoda: Troodontidae) on the new material from the Yixian Formation of western Liaoning, China. PeerJ 6: e4977. doi:10.7717/peerj.4977

    Described a new specimen of Sinovenator changii and recovered Mei, Sinovenator and Sinusonasus as successive early-branching troodontids, not a clade.

    yin2018a
  4. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.

    Reviews Sinovenatorinae, noting that analyses seldom agree on its membership and that some place it within Troodontinae.

    jones2026c