A new species of extinct whale that inhabited seas covering present-day Egypt has been named after the famous pharaoh Tutankhamun.
The 41 million-year-old fossil was unearthed near Faiyum, a city around 60 miles (100 kilometers) southwest of Cairo, by an international team of scientists.
With a length of around eight feet (2.5 meters) and an estimated body mass of 187 kilos (29.4 stone), it is the smallest known basilosaurid whale to date – and one of the oldest records of that family from Africa.
The research team explained that Basilosauridae, a group of extinct fully aquatic whales, represent a “crucial” stage in whale evolution as they transitioned from land to sea.
They developed fish-like characteristics – such as a streamlined body, a strong tail, flippers, and a tail fin- and had the last hind limbs visible enough to be recognized as “legs”, which were not used for walking but possibly for mating.
The new specimen consists of a skull, jaws, hyoid bone, and the atlas vertebra of a small-sized subadult basilosaurid whale which is embedded in an intensively compacted limestone block.
Despite its relatively small size, the whale dubbed Tutcetus rayanensis has provided “unprecedented” insights into the life of early whales.
The researchers explained that the name was inspired by both Egyptian history and the location where it was found.
The genus name, Tutcetus, combines “Tut” – referring to the Egyptian Pharaoh Tutankhamun – and “cetus,” Greek for whale, highlighting the specimen’s small size and subadult status.
The researchers said the name also marks the discovery of Tutankhamun’s tomb a century ago and coincides with the impending opening of the Grand Egyptian Museum in Giza.
The species name, rayanensis, refers to the Wadi El-Rayan Protected Area in Fayum where it was found.
Project leader Professor Hesham Sallam, of the American University in Cairo, said: “Whales’ evolution from land-dwelling animals to beautiful marine creatures embodies the marvellous adventurous journey of life.
“Tutcetus is a remarkable discovery that documents one of the first phases of the transition to a fully aquatic lifestyle that took place in that journey.”
Lead author Mohamed Antar, of Mansoura University in Egypt, said: “Tutcetus significantly broadens the size range of basilosaurid whales and reveals considerable disparity among whales during the middle Eocene period.
“The investigation of the older layers in Fayum layers may reveal the existence of an older assemblage of early whale fossils, potentially influencing our current knowledge of the emergence and dispersal of whales”.
Co-author Sanaa El-Sayed, a Ph.D. student at the University of Michigan, said: “The relatively small size of Tutcetus is either primitive retention or could be linked to the global warming event known as the Late Lutetian Thermal Maximum, or LLTM.
“This ground-breaking discovery sheds light on the early evolution of whales and their transition to aquatic life”.
Analysis of Tutcetus’s teeth and bones, using CT scans, enabled the team to reconstruct the growth and development pattern of the species, providing an “unparalleled” understanding of the life history of early whales.
They say the rapid dental development and small size of Tutcetus suggest a “precocial lifestyle” with a fast pace of life history for early whales.
The team said the discovery of Tutcetus also contributes to the understanding of the basilosaurids’ early success in the aquatic environment, and their ability to adapt to new niches after severing their ties to the land.
The team’s findings, published in the journal Communications Biology, suggest that the transition likely occurred in the sub-tropics.
Study co-author Abdullah Gohar, of Mansoura University, said: “Modern whales migrate to warmer, shallow waters for breeding and reproduction, mirroring the conditions found in Egypt 41 million years ago.
“This supports the idea that what is known as now Fayum was a crucial breeding area for ancient whales, possibly attracting them from various locations and, in turn, drawing in larger predatory whales like Basilosaurus”.
Co-author Dr. Erik Seiffert, of the University of Southern California, added: “The Eocene fossil sites of Egypt’s Western Desert have long been the world’s most important for understanding the early evolution of whales and their transition to a fully aquatic existence.
“The discovery of Tutcetus demonstrates that this region still has so much more to tell us about the fascinating story of whale evolution.”
Produced in association with SWNS Talker
