Open Paleo

Leaellynasaura

Rich & Vickers-Rich, 1989 lee-EL-in-a-SAWR-a

Named after Leaellyn Rich, the daughter of paleontologists Tom Rich and Patricia Vickers-Rich, combined with Greek sauros (lizard); meaning "Leaellyn's lizard"

121.4–100.5 million years ago Aptian–Albian, Early Cretaceous
Early Cretaceous stages

Leaellynasaura is a genus of small herbivorous ornithischian dinosaurs from the late Aptian to early Albian stage of the Early Cretaceous, around 118-110 million years ago. It was first discovered in Dinosaur Cove, Australia. The only known species is Leaellynasaura amicagraphica. It was described in 1989, and named after Leaellyn Rich, the daughter of the Australian paleontologist couple Tom Rich and Patricia Vickers-Rich who discovered it. The specific name, amicagraphica, translates to "friend writing" and honors both the Friends of the Museum of Victoria and the National Geographic Society for their support of Australian paleontology.

Diagnosis

  1. Distal end of the femur more anteroposteriorly compressed than in all other hypsilophodontids
  2. Ridges present on both sides of unworn upper cheek teeth, a condition shared only with Othnielia among hypsilophodontids
  3. Upper cheek tooth ridges lack two discrete size classes (unlike Atlascopcosaurus), being equally developed on both sides of the unworn tooth
  4. Ridges cover the entire internal and external (lingual and buccal) surfaces of the crown rather than being restricted to marginal denticles
  5. Lacks a single primary ridge markedly stronger than the others, and bears a maximum of five ridges rather than a minimum of eight as in several other hypsilophodontids

Species

Leaellynasaura amicagraphica Rich & Vickers-Rich, 1989

Type species

From Latin 'amicus' meaning 'friend' and Greek 'graphikos' relating to writing or imagery, translating as 'friend writing', honoring both the Friends of the Museum of Victoria and the National Geographic Society for their support of Australian paleontology.

Holotype
NMV P185991 , Museums Victoria
Material
Partial skull: left maxilla with eight cheek teeth, left pterygoid, left jugal, and possibly vomer and left premaxilla.
Horizon
Eumeralla Formation, Aptian–Albian, Early Cretaceous , 121.4–100.5 million years ago
Locality
Slippery Rock, Dinosaur Cove, Victoria, Australia Rich and Vickers-Rich (1989) date the Otway Basin coastal sites, Dinosaur Cove among them, as "latest Aptian–early Albian" on palynological evidence.

References

  1. Herne, M. C.; Nair, J. P.; Evans, A. R.; Tait, A. M. (2019). New small-bodied ornithopods (Dinosauria, Neornithischia) from the Early Cretaceous Wonthaggi Formation (Strzelecki Group) of the Australian-Antarctic rift system, with revision of Qantassaurus intrepidus Rich and Vickers-Rich, 1999. Journal of Paleontology 93(3): 543-584. Cambridge University Press (CUP). doi:10.1017/jpa.2018.95

    Places the species in the "early Albian Eumeralla Formation" in its text and in the "lower Aptian" in its Table 5.

    herne2019a
  2. Rich, T. H.; Vickers-Rich, P. (1989). Polar dinosaurs and biotas of the Early Cretaceous of southeastern Australia. National Geographic Research 5(1): 15-53. rich1989a
  3. Paul, G. S. (2024). The Princeton Field Guide to Dinosaurs (3rd ed.). Princeton University Press.

    Source of the mass estimate.

    paul2024a