''Sefapanosaurus'' was an early, herbivorous

sauropodomorph Sauropodomorpha ( ; from Greek, meaning "lizard-footed forms") is an extinct clade of long-necked, herbivorous, saurischian dinosaurs that includes the sauropods and their ancestral relatives. Sauropods generally grew to very large sizes, had lon ...

dinosaur occurring in the southern regions of Gondwana some 200 million years ago in the

Late Triassic The Late Triassic is the third and final epoch of the Triassic Period in the geologic time scale, spanning the time between Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch and followed by the Early Jurassic Epoch. ...

Early Jurassic The Early Jurassic Epoch (geology), Epoch (in chronostratigraphy corresponding to the Lower Jurassic series (stratigraphy), Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic-J ...

. The sauropodomorphs were the dominant terrestrial herbivores throughout much of the Mesozoic Era, from their origins in the mid-

Triassic The Triassic ( ) is a geologic period and system (stratigraphy), system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago (Year#Abbreviations yr and ya, Mya), to the beginning of the Jurassic Period 201.36 ...

(approximately 230 Ma) until their decline and fall at the end of the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

(approximately 66 Ma). A distinctive feature of this dinosaur is the cross-shaped astragalus or

talus bone The talus (; Latin for ankle or ankle bone), talus bone, astragalus (), or ankle bone is one of the group of foot bones known as the tarsus. The tarsus forms the lower part of the ankle joint. It transmits the entire weight of the body from the ...

in its ankle. The generic name is derived from the

Sesotho Sotho () or Sesotho () or Southern Sotho is a Southern Bantu language of the Sotho–Tswana ("S.30") group, spoken primarily by the Basotho in Lesotho, where it is the national and official language; South Africa (particularly the Free ...

word ''sefapano'', meaning ‘cross’ and the Greek word ''saurus'', meaning 'lizard'. The specific name refers to Zastron, the type locality, where the specimen was discovered.

History of study

This new genus was described in the 23 June 2015 issue of '

Zoological Journal of the Linnean Society The ''Zoological Journal of the Linnean Society'' is a monthly peer-reviewed scientific journal covering zoology published by Oxford University Press on behalf of the Linnean Society. The editor-in-chief is Maarten Christenhusz (Linnean Society). ...

' in an essay titled 'A new basal sauropodiform from South Africa and the phylogenetic relationships of basal sauropodomorphs'. A portion of the left foot and four partial skeletons, including several pieces of spine and limbs, were excavated from the

Elliot Formation The Elliot Formation is a geological formation and forms part of the Stormberg Group, the uppermost geological group that comprises the greater Karoo Supergroup. Outcrops of the Elliot Formation have been found in the northern Eastern Cape, south ...

in the late 1930s in the

Zastron Zastron is a small agricultural town in the Free State province of South Africa, some 30 km from the border of Lesotho. It is situated at the foot of Aasvoëlberg (Vulture Mountain), named for the rare Cape vultures attracted by a feeding p ...

district in South Africa, some from the Lesotho border. Until a few years ago these formed part of the large fossil collection curated by the Evolutionary Studies Institute (ESI) at

Wits University The University of the Witwatersrand, Johannesburg (), is a multi-campus South African public research university situated in the northern areas of central Johannesburg. It is more commonly known as Wits University or Wits ( or ). The university ...

. When finally studied, the remains were thought to be those of the dinosaur '' Aardonyx''. Further study determined that the remains represented a new dinosaur genus which was intermediate between early bipedal sauropodomorphs and the later giant quadruped sauropods, adding to the list of transitional sauropodomorphs from

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

and

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...

, and further clarifying their diversification.

Phylogeny

The following cladogram shows the position of ''Sefapanosaurus'' within Massopoda, according to Oliver W. M. Rauhut and colleagues, 2020:

References

{{Taxonbar, from=Q20440451 Sauropodomorphs Early Jurassic dinosaurs of Africa Jurassic South Africa Fossils of South Africa Fossil taxa described in 2015