Eotyrannus
From Greek eos (dawn) + tyrannos (tyrant): 'dawn tyrant', indicating it is an early member of the tyrannosaur lineage.
Eotyrannus is a genus of tyrannosauroid theropod dinosaur hailing from the Early Cretaceous Wessex Formation beds, included in Wealden Group, located in the southwest coast of the Isle of Wight, United Kingdom. The remains (MIWG 1997.550), consisting of assorted skull, axial skeleton and appendicular skeleton elements, from a juvenile or subadult, found in a plant debris clay bed, were described by Stephen Hutt and colleagues in early 2001. The etymology of the generic name refers to the animal's classification as an early tyrannosaur or "tyrant lizard", while the specific name honors the discoverer of the fossil.
Diagnosis
- Lateral surface of the dentary bearing five shallow arcuate furrows that extend anterodorsally from a common origin on the ventral part of the bone
- Large, block-like humeral entepicondyle projecting medially
- Distal tibia with a distoproximally aligned channel demarcated laterally by a low ridge, located close to the lateral border of the shaft
Species
Eotyrannus lengi Hutt et al., 2001
Type species
Named for Gavin Leng, the local collector who discovered the fossil on the Isle of Wight and revealed its location to researchers.
- Holotype
- MIWG 1997.550 , Dinosaur Isle Museum
- Material
- Partial skeleton including skull elements (right premaxilla, partial left maxilla, right lacrimal, fused nasals, left quadrate, both dentaries, isolated teeth), axial vertebrae, both scapulae, left coracoid, both humeri, partial forelimbs with carpals/metacarpals/phalanges, fragmentary ilium, partial left tibia and fibula, metatarsals and phalanges
- Horizon
- L11 Bed, Wessex Formation, Barremian, Early Cretaceous , 125.8–121.4 million years ago
- Locality
- 100 m east of Grange Chine, Isle of Wight, United Kingdom
Synonyms of the genus
| Name | Type | Reason |
|---|---|---|
| Fusinasus | nomen nudum | Informal name used for material now considered referable to Eotyrannus. |
| Gavinosaurus | nomen nudum | Informal name used for material now considered referable to Eotyrannus. |
| Kittysaurus | nomen nudum | Informal name used for material now considered referable to Eotyrannus. |
| Lengosaurus | nomen nudum | Informal name used for material now considered referable to Eotyrannus. |
References
- Hutt, S.; Naish, D.; Martill, D. M.; Barker, M. J.; Newbery, P. (2001). A preliminary account of a new tyrannosauroid theropod from the Wessex Formation (Early Cretaceous) of southern England. Cretaceous Research 22(2): 227-242. Elsevier BV. doi:10.1006/cres.2001.0252 hutt2001a
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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
Comprehensive osteological redescription of the holotype with an emended diagnosis; recovers Eotyrannus as a non-tyrannosaurid tyrannosauroid and rejects a megaraptoran affinity.
naish2022a -
Paul, G. S. (2024). The Princeton Field Guide to Dinosaurs (3rd ed.). Princeton University Press.
Source of the mass estimate, and the appearance features.
paul2024a