# Protoceratops andrewsi

> A sheep-sized horned dinosaur with a large frill and a parrot-like beak from the Late Cretaceous Gobi Desert of Mongolia. Hundreds of skeletons are known, including one locked in combat with a Velociraptor.

- Classification: Dinosauria (clade) > Ornithischia (clade) > Ceratopsia (clade) > Protoceratopsidae (family) > Protoceratops (genus) > Protoceratops andrewsi (species)
- Length: 2–2.5 m
- Hip height: 0.6–0.8 m
- Mass: 62–104 kg
- Age: 75–71 million years ago (Late Cretaceous)
- Fossils found in: Djadokhta Formation (Ömnögovi Province); Mongolia
- Diet: herbivore
- Described: Walter Granger & William K. Gregory, 1923

Canonical page: https://dinodex.club/dinosaurs/protoceratops-andrewsi
Last updated: 2026-09-27

## Overview

Protoceratops andrewsi lived among the sand dunes of the Djadokhta Formation in what is now the Gobi Desert of Mongolia, in the Late Cretaceous. The photographer James B. Shackelford of the American Museum's Central Asiatic Expedition found the first skull at the Flaming Cliffs (Shabarakh Usu) in 1922, and Walter Granger and William K. Gregory named it in 1923 after the expedition leader Roy Chapman Andrews.

It was an early relative of the large horned dinosaurs, about 2 m long, with a big head, a bony frill and a small bump in place of a nose horn. The frill and nasal bump grew faster than the rest of the body as the animal matured, which suggests they were used as social or sexual signals (Hone et al. 2016).

Protoceratops is one of the best known dinosaurs, with many skeletons from hatchlings to adults. Its eggs were originally soft-shelled (Norell et al. 2020), and the famous "Fighting Dinosaurs" specimen preserves one locked in combat with Velociraptor.

## Name meaning

"First horned face", from Greek protos, keras and ops; andrewsi after Roy Chapman Andrews, leader of the Central Asiatic Expeditions (Granger & Gregory 1923).

## Sources

1. (2026). Paleobiology Database: Protoceratops andrewsi occurrences and type collection 46152. The Paleobiology Database (paleobiodb.org), data service 1.2, accessed 2026-09-23. https://paleobiodb.org/data1.2/occs/list.txt?taxon_name=Protoceratops%20andrewsi&show=coords,paleoloc,strat,loc,ref&pgm=gplates
2. (2026). Wikipedia: Protoceratops. Wikipedia (English), accessed 2026-09-24. https://en.wikipedia.org/wiki/Protoceratops
3. Dashzeveg, D., Dingus, L., Loope, D. B., Swisher, C. C., III, Dulam, T. & Sweeney, M. R. (2005). New stratigraphic subdivision, depositional environment, and age estimate for the Upper Cretaceous Djadokhta Formation, southern Ulan Nur Basin, Mongolia. American Museum Novitates 3498: 1-31. https://digitallibrary.amnh.org/server/api/core/bitstreams/0df4baac-12e4-44ae-8ef7-3328b22e8604/content
4. Granger, W. & Gregory, W. K. (1923). Protoceratops andrewsi, a pre-ceratopsian dinosaur from Mongolia, with an appendix on the structural relationships of the Protoceratops beds. American Museum Novitates 72: 1-9.
5. Hone, D. W. E., Wood, D. & Knell, R. J. (2016). Positive allometry for exaggerated structures in the ceratopsian dinosaur Protoceratops andrewsi supports socio-sexual signaling. Palaeontologia Electronica 19.1.5A. https://doi.org/10.26879/591
6. Norell, M. A., Wiemann, J., Fabbri, M., Yu, C., Marsicano, C. A., Moore-Nall, A., Varricchio, D. J., Pol, D. & Zelenitsky, D. K. (2020). The first dinosaur egg was soft. Nature 583: 406-410. https://doi.org/10.1038/s41586-020-2412-8
7. Paul, G. S. (2016). The Princeton Field Guide to Dinosaurs (2nd edition). Princeton University Press.

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Cite as: "Protoceratops andrewsi". DinoDex. https://dinodex.club/dinosaurs/protoceratops-andrewsi (updated 2026-09-27).