Ostromia

Foth & Rauhut, 2017 Oss-trom-ee-uh Nomen dubium

Named in honor of John Ostrom, the influential American paleontologist who identified the holotype specimen as an Archaeopteryx

149.2–143.1 million years ago Tithonian, Late Jurassic

Late Jurassic stages

Ostromia is a genus of feathered theropod dinosaur containing a single species, Ostromia crassipes, based on the Haarlem specimen. Recovered from the Late Jurassic Painten Formation of Germany, it was named by Christian Foth and Oliver Rauhut in 2017.

Species

Ostromia crassipes Foth & Rauhut, 2017 Nomen dubium

Type species

From Latin 'crassipes' meaning 'thick-footed', combining 'crassus' ('thick') and 'pes' ('foot'), derived from the original name Pterodactylus crassipes given in 1857.

Holotype: TM 6928, TM 6929 , Teylers Museum
Material: Slab and counterslab of partial skeleton with feather impressions.
Horizon: Painten Formation, Tithonian, Late Jurassic , 149.2–143.1 million years ago
Locality: Jachenhausen, Bavaria, Germany

References

Foth, C.; Rauhut, O. W. M. (2017). Re-evaluation of the Haarlem Archaeopteryx and the radiation of maniraptoran theropod dinosaurs. BMC Evolutionary Biology 17(1). Springer Science and Business Media LLC. doi:10.1186/s12862-017-1076-y foth2017a
Foth, C.; Rauhut, O. W. M. (2026). Considerations on the taxonomy of Late Jurassic Avialae (Theropoda) from the Solnhofen Archipelago. Fossil Record 29(2): 731-758. Pensoft Publishers. doi:10.3897/fr.29.200245
The describing authors now classify the Haarlem specimen as Avialae indet., as it lacks any indisputable diagnostic features.
foth2026a
O'Connor, J.; Marugán-Lobón, J. (2026). Evaluating variation in Solnhofen avialans. Biology Letters 22(3): 20250601. doi:10.1098/rsbl.2025.0601
Morphometrics cluster the Haarlem specimen with Archaeopteryx rather than Anchiornis; the case for a distinct genus is called equivocal.
o'connor2026a
Paul, G. S. (2024). The Princeton Field Guide to Dinosaurs (3rd ed.). Princeton University Press.
Source of the body length and mass estimates.
paul2024a
Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.
Source of the hip height estimate.
jones2026c