In 2000, an extraordinary discovery was made in northern India’s Kashmir Valley: the giant fossil skull of an extinct elephant, which sheds light on a little-known chapter in elephant evolutionary history. The skull, found buried alongside 87 stone tools used by prehistoric humans, was excavated under the direction of Dr. Ghulam Bhat from the University of Jammu. Recently, an international team of scientists from prestigious institutions, including the Florida Museum of Natural History, the British Museum, the University of York, the Natural History Museum in London, and Dr. Steven Zhang from the University of Helsinki, undertook an in-depth study of this Kashmir skull to better understand its age and evolutionary context. Their findings, published in the Journal of Vertebrate Paleontology, have added a new layer of knowledge to the complex evolutionary story of elephants.
The fossilized skull is remarkable for a variety of reasons, most notably its size and distinctive features. According to Dr. Steven Zhang, a paleontologist from the University of Helsinki’s Department of Geosciences and Geography, the skull is unmistakably from a member of the Palaeoloxodon genus, commonly known as the straight-tusked elephants, which were among the largest land mammals to ever roam the Earth. These elephants were formidable creatures, with full-grown adults reaching a height of around 4 meters at the shoulder and weighing between 9 to 10 tonnes. Yet, what puzzled scientists was the lack of a prominent skull crest, a feature that typically characterizes other Palaeoloxodon skulls, particularly those found in India.
Over the past few decades, there has been ongoing debate among experts regarding the development of the skull crest in Palaeoloxodon species. This crest, which projects forward from the skull roof, appears to become more pronounced as the elephant matures, particularly in males. The varying extent of this feature has led to questions about whether it could be used to differentiate between species and determine their evolutionary position on the elephant family tree. Recent studies, however, suggest that the size of the skull crest correlates with both developmental and sexual maturity. This finding implies that by examining the wear and tear on an elephant’s teeth, scientists can more accurately age specimens and compare skulls from individuals at similar levels of maturity.
Upon further examination of the Kashmir skull, Zhang and his colleagues concluded that this individual was an adult male in the prime of its life, based on the size of the skull and the condition of its wisdom teeth. Despite the skull’s impressive size and the animal’s advanced age, the absence of a pronounced skull crest set this specimen apart from other mature Palaeoloxodon males found in Europe and India. This led the team to hypothesize that the Kashmir skull could represent a previously unknown species of straight-tusked elephant.
Interestingly, the team found that the features of the Kashmir skull bore a remarkable resemblance to another obscure fossil discovered in Turkmenistan in the 1950s. This earlier specimen had been the subject of considerable debate among paleontologists. While the lack of a prominent skull crest was a notable similarity between the Turkmen skull and the Kashmir skull, the rest of the features closely mirrored those of P. antiquus, a well-known European species of straight-tusked elephant. Initially, some researchers suggested that the Turkmen specimen was simply an aberrant individual of P. antiquus. However, with the discovery of the Kashmir skull, the team now believes that the two fossils may represent a distinct species, Palaeoloxodon turkmenicus, which had a broad geographic distribution extending from Central Asia to the northern Indian Subcontinent.
Dr. Advait Jukar, the study’s lead author from the Florida Museum of Natural History, highlighted that the similarities between the Kashmir and Turkmen fossils were so striking that it was now possible to propose the existence of P. turkmenicus as a unique species. This new understanding fills a gap in the evolutionary history of the Palaeoloxodon genus and may change how we view the distribution and diversity of straight-tusked elephants across Eurasia. The team’s research also included measuring protein decomposition in the tooth enamel of the Kashmir skull, which helped them determine that it dates to the Middle Pleistocene period, approximately 300,000 to 400,000 years ago. This age is remarkably close to the estimated age of the Turkmen skull, lending further support to the idea that the two specimens represent the same species.
The Palaeoloxodon genus first evolved in Africa around 1 million years ago. The earliest African forms of these elephants had a narrow, convex forehead and lacked a well-developed skull crest. Over time, as the genus spread into Europe and Asia, the characteristics of Palaeoloxodon evolved, with later species exhibiting broader, flatter foreheads and prominent crests jutting forward from the roof of the skull. These features are most famously seen in P. antiquus, a species that thrived in Europe during the Pleistocene. However, the lack of a well-developed skull crest in the Kashmir and Turkmen fossils suggests that these specimens could represent an intermediate form, a “missing link” in the evolutionary development of straight-tusked elephants.
The findings of this research are significant not only for understanding the evolutionary trajectory of elephants but also for shedding light on the broader ecological and environmental contexts in which these magnificent creatures lived. The Palaeoloxodon species were massive megaherbivores that played important roles in their ecosystems. As they moved across vast areas, they likely shaped the landscapes they inhabited through their feeding habits and migrations. The discovery of the Kashmir skull, along with the associated stone tools, also hints at the interactions between prehistoric humans and these megafauna. The fact that the skull was found alongside human-made tools suggests that humans may have hunted or scavenged these elephants, adding another layer to the story of human evolution and the megafauna extinction event that occurred around 10,000 years ago.
Reference: Advait M. Jukar et al, A remarkable Palaeoloxodon (Mammalia, Proboscidea) skull from the intermontane Kashmir Valley, India, Journal of Vertebrate Paleontology (2024). DOI: 10.1080/02724634.2024.2396821