Ceratocaudia

Ceratocaudia (lit.'horned tail') is a genus of macronarian sauropod dinosaur from the Jurassic Kaladongar Formation of Gujarat, India. The genus contains a single species, the type species Ceratocaudia antiqua, known from a partial skeleton.^[1]

The Ceratocaudia holotype specimen was collected from the low energy estuarine sediments of Khadir Uplift of Kaladongar Formation in Kutch district of Gujarat, India. The holotype specimen consists several cervical (neck) and caudal (tail) vertebrae, an isolated chevron, and elements of the appendicular skeleton including an interclavicle, an ulna (forearm bone), metacarpals (finger bones), femora (thighbones), tibiae, fibulae (lower leg bones), and a metatarsal (toe bone). They are housed in the Indian Institute of Technology Bombay in Mumbai, India, where they are permanently accessioned under the codes IITBR3 to IITBR59.^[1]

In 2026, Abhishek Natarajan and colleagues described the remains as belonging to a new genus and species of sauropod dinosaurs. The generic name, Ceratocaudia, comes from the Ancient Greek word κέρας, meaning 'horn', and the Latin word cauda, meaning 'tail', after the horn-like crest on the anterior caudal neural spine. The specific name, antiqua, is a Latin word meaning 'ancient'.^[1]

The Ceratocaudia holotype is estimated to be about 7 metres (23 ft) long, making it one of the smallest known macronarians. There is a possibility that it represents a dwarf taxon.^[1]

Based on histological analysis and the presence of a non-traumatic pathology, the holotype appears to have been a senescent (old) individual. A reconstructed muscle model of the tail suggests it was used as a mild predator deterrent.^[1]

The sediments in which Ceratocaudia was found, also consists of abundant petrified woods and bivalves that lived in brackish waters like Protocardia and Indocorbula. The Khadir Uplift of different horizon but of the same age, has yielded a large fragmentary sauropod which is estimated to be 20 metres long, aswell as a hybodont shark Strophodus magnus , the presence of a large contemporary sauropod suggest nieche partitioning between it and Ceratocaudia, though its unknown what ecological role they had in their environment due both lacking cranial materials.^[1]

To determine the relationships of Ceratocaudia, Natarajan et al. (2026) placed in within the phylogenetic matrices of Mannion & Moore (2025)^[2] and Pérez Moreno et al. (2023).^[3] Both analyses placed Ceratocaudia within the Macronaria, outside the Titanosauriformes, making it one of the oldest such sauropods and adding to the evidence of a global pre-Bajocian distribution of macronarians. The reduced strict consensus results of the Mannion & Moore (2025) dataset, pruning 21 taxa, is shown in the cladogram below:^[1]