Open Paleo

Tanycolagreus

Carpenter et al., 2005 tan-ee-KOL-uh-gree-us

From Greek 'tany' meaning 'long' or 'stretched out', 'kolon' meaning 'limb', and 'agreus' meaning 'hunter', referring to the greater length of its forelimbs and hindlimbs compared to Coelurus

154.8–143.1 million years ago Kimmeridgian–Tithonian, Late Jurassic
Late Jurassic stages

Tanycolagreus is a genus of coelurosaurian theropod dinosaur from the Late Jurassic (Kimmeridgian to Tithonian) of the U.S. states of Wyoming, Utah, and Colorado.

Under dispute

The placement of Tanycolagreus is unsettled. Naish and Cau (2022) recover it with Coelurus in a Coeluridae at the base of Tyrannosauroidea, and Cau (2024) treats it as a tyrannosauroid, while Delcourt and colleagues (2025), under implied weights, recovered it among the earliest-branching Maniraptoromorpha with Santanaraptor. It is placed conservatively at Coelurosauria incertae sedis.

Diagnosis

  1. Short, deep-bodied premaxilla with narial foramen at base of nasal process
  2. T-shaped quadratojugal
  3. Centrodiapophyseal lamina on dorsals
  4. Absence of pleurocoel on anterior dorsals
  5. Posterior caudal prezygapophyses elongated to approximately one-third centrum length
  6. Straight humeral shaft

Species

Tanycolagreus topwilsoni Carpenter et al., 2005

Type species

Named for George Eugene 'Top' Wilson, the father of an anonymous benefactor who financially supported the scientific research and donated the fossil to science.

Holotype
TPII 2000-09-29 , Thanksgiving Point Institute (North American Museum of Ancient Life)
Material
Partial skeleton
Horizon
Morrison Formation, Kimmeridgian–Tithonian, Late Jurassic , 154.8–143.1 million years ago
Locality
Bone Cabin Quarry West, Wyoming, United States

References

  1. Carpenter, K.; Miles, C. A.; Cloward, K. C. (2005). New small theropod from the Upper Jurassic Morrison Formation of Wyoming. The Carnivorous Dinosaurs (Carpenter, K., ed.) 23-48. Indiana University Press, Bloomington. carpenter2005a
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.

    Source of the hip height estimate.

    jones2026c
  3. Cau, A. (2024). A Unified Framework for Predatory Dinosaur Macroevolution. Bollettino della Società Paleontologica Italiana 63(1): 1-19. doi:10.4435/BSPI.2024.08

    Recovered Tanycolagreus within Tyrannosauroidea.

    cau2024a
  4. 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 Tanycolagreus near the base of Tyrannosauroidea, with Coelurus in reduced Coeluridae.

    hartman2019a
  5. Delcourt, D.; Grillo, O. N.; Hendrickx, C.; Kellermann, M.; Langer, M. C. (2025). The coelurosaur theropods of the Romualdo formation, early Cretaceous (Aptian) of Brazil: Santanaraptor placidus meets Mirischia asymmetrica. The Anatomical Record ar.70085. Wiley. doi:10.1002/ar.70085

    Recovered Tanycolagreus among earliest-branching Maniraptoromorpha with Santanaraptor and Mirischia.

    delcourt2025a
  6. Naish, D.; Cau, A. (2022). The osteology and affinities of Eotyrannus lengi, a tyrannosauroid theropod from the Wealden Supergroup of southern England. PeerJ 10: e12727. PeerJ. doi:10.7717/peerj.12727

    Recovered Tanycolagreus with Coelurus in a Coeluridae at the base of Tyrannosauroidea.

    naish2022a