Jaklapallisaurus asymmetricus was an early sauropodomorph from the Upper Triassic Upper Maleri Formation of central India. Its type specimen preserves two vertebrae and much of a right hind limb. The ankle and foot provide enough anatomy to recognise a distinct genus and compare it with South American unaysaurids, but not enough to measure the whole animal or reconstruct its head.
A 2024 redescription refined the anatomy and corrected the ending of the species name from asymmetrica to asymmetricus. Its proposed relationship with Brazilian dinosaurs is informative for the early spread of sauropodomorphs across Gondwana, although the position of the wider group remains open to revision. It has a place in the dinosaur catalogue as a Triassic form known chiefly from its hind limb.
Quick facts
| Scientific name | Jaklapallisaurus asymmetricus Novas et al., 2011 |
|---|---|
| Group | Dinosauria, Sauropodomorpha; proposed Unaysauridae |
| Age | Early Norian, approximately 225–215 million years ago |
| Formation | Upper Maleri Formation, Telangana, India |
| Holotype | ISIR 274, collected near Jaklapalli |
| Known material | Two vertebrae and parts of the right hind limb and foot |
| Tibia | 29.4 centimetres long |
| Diet | Plant-based or mixed feeding is possible; direct dietary evidence is absent |
| Main uncertainty | Skull, forelimbs, most of the trunk and tail are unknown |
What can the partial skeleton tell us?
It includes two vertebrae, the lower end of a femur, tibia, astragalus, four metatarsals and two toe phalanges. The skull, forelimbs and most of the body are missing.
The ankle bone, tibia and metatarsal proportions distinguish the specimen and allow comparisons with other early sauropodomorphs. They do not directly reveal its total length or whole-body posture.
The neural arches are fused or tightly joined to the vertebral centra. This suggests the animal was not a very young hatchling, but the preserved bones cannot establish its age in years.
Its main analysis paired Jaklapallisaurus with Brazilian Macrocollum and grouped them with Unaysaurus. The exact position of Unaysauridae among early sauropodomorphs was less stable.
The bones from the Pranhita–Godavari Valley
Indian palaeontologist T. S. Kutty collected the holotype ISIR 274 near the town of Jaklapalli. Fernando Novas, Martín Ezcurra, Sankar Chatterjee and Kutty described it in a study of dinosaurs from the Upper Maleri and Lower Dharmaram formations. The work belongs to a 2010 volume that appeared in 2011.
The genus name combines the locality name Jaklapalli with a Greek-derived word for lizard. The original description used the species ending asymmetrica. In the 2024 redescription, the spelling became asymmetricus to agree with the masculine grammatical gender assigned to Jaklapallisaurus. This is a nomenclatural correction, not the naming of a new species.
The holotype consists of a probable front dorsal vertebra, a front caudal vertebra, the lower end of a right femur, a right tibia with its astragalus, four metatarsals and the first phalanges of the first and second toes. The tibia is 29.4 centimetres long; the complete second metatarsal measures 14.3 centimetres.
The neural arches of the two vertebrae are fused to, or joined by very tight sutures with, their centra. That indicates some skeletal maturity. It does not provide an exact age, and the specimen should not be labelled fully adult solely from those two vertebrae.
Why the ankle and foot matter
The species name refers to the marked asymmetry of the astragalus when viewed from below. This ankle bone joined the lower leg to the foot. Its shape, the lower end of the tibia and the proportions of the metatarsals provide the main anatomical basis for comparisons with other early sauropodomorphs.
The foot was relatively slender. The second metatarsal is straight and noticeably thinner than in many later plateosaurian sauropodomorphs. The metatarsus as a whole is shorter than that of Nambalia roychowdhurii, another dinosaur from the same deposits. The first toe was not absent: its metatarsal and first phalanx are preserved.
A hind limb alone cannot settle locomotion. Early sauropodomorphs commonly had long hind limbs and shorter forelimbs and could move bipedally, but no shoulder girdle or forelimb is known for Jaklapallisaurus. A reconstruction therefore borrows its broad posture from relatives rather than measuring a complete gait from this animal.
A changing view of its relationships
The original analysis placed Jaklapallisaurus among Plateosauridae with Unaysaurus and Plateosaurus, without resolving their order. Later data matrices moved the Indian genus between the base of Plateosauria and positions outside that group.
The 2024 redescription added detailed characters from all the preserved bones. Its main analysis recovered Jaklapallisaurus as the sister taxon of the Brazilian Macrocollum; the pair grouped with Unaysaurus in Unaysauridae. Support for the pair was stronger than support for the family as a whole or its exact position relative to Plateosauridae.
Thus, the relationship among these three southern genera is the more stable part of the result, while the branch’s place among early sauropodomorphs can still change. Comparison with the better-known Plateosaurus helps explain the general body plan, but it cannot supply the missing anatomy of the Indian fossil.
Age, Gondwana and diet
The Upper Maleri Formation belongs to the Pranhita–Godavari Basin. Current faunal correlations favour an early Norian age of about 225 million years, while a broader interval of roughly 225–215 million years is appropriate for the correlated beds. No radiometric date directly measures the individual skeleton, so a narrow decimal age would imply greater precision than the evidence supports.
Related sauropodomorphs lived at the same broad time in what is now Brazil. During the Triassic Period, India and South America were parts of Gondwana, and connected southern land areas allowed terrestrial animals to spread. The fossils are consistent with faunal exchange between the regions, but they do not establish a migration route or its direction.
The skull and teeth of Jaklapallisaurus are unknown, so its diet cannot be read directly from the type. Plant eating or mixed feeding is plausible by comparison with early sauropodomorphs, but neither stomach contents nor feeding traces have been reported. Neck length, tail proportions, skin, colour and social behaviour are likewise not preserved.
What remains uncertain
The useful evidence is concentrated in the vertebrae, lower leg, ankle and foot. These bones support the identification of a distinct early sauropodomorph and make its relationships testable. The partial material does not provide a reliable total length, mass, skull shape or complete posture.
Jaklapallisaurus matters not because it was a giant, but because its articulated lower leg and foot come from a significant Triassic region and help connect Indian fossils with related South American forms. The missing body should remain a reconstruction rather than being mistaken for a discovered skeleton.
Frequently asked questions
Which spelling of the species name is current?
The 2024 redescription uses Jaklapallisaurus asymmetricus. Asymmetrica is the original spelling, corrected to agree grammatically with the genus name.
Has a complete skeleton been found?
No. The holotype includes two vertebrae and parts of the right hind limb and foot. The skull, forelimbs and most of the trunk and tail are unknown.
Was Jaklapallisaurus a direct ancestor of sauropods?
It was an early sauropodomorph, within the wider lineage that also includes sauropods. The named genus is not established as a direct ancestor of later forms.
Why is it linked with dinosaurs from Brazil?
The 2024 analysis compared its ankle and foot with Macrocollum and Unaysaurus. Their relationships are consistent with early sauropodomorph diversity across Gondwana, but do not reveal a migration route.