CAIRO — With the participation of an international team of researchers, an Egyptian research team at the Mansoura University Vertebrate Paleontology Center (MUVP) has recently discovered the oldest fossil of the ancestors of the Egyptian cobra snake, as well as the largest ever legless lizard, both dating back 37 million years.
Mansoura University stated in a Facebook statement that the discovery also included new specimens of the reninotite snake. It noted that the discovery was published Feb. 16 in the Journal of Vertebrate Paleontology (JVP), which specializes in vertebrate fossils.
Marwa El-Hares, member of the MUVP team and the main author of the study, told Al-Monitor that this is the first time that fossils of animals of the Squamata genus — an animal rank belonging to reptiles with renewed scales — have been found, and added that they are divided into two groups — lizards and serpents.
This discovery, she said, unveils the life and development of squamous creatures in the Fayum Depression —a large basin formed in the limestone plateau of the Western Desert, southwest of Cairo — during the Paleogene era, which is the first of three eras of the Cenozoic era (66 to 23 million years ago).
In the Fayum Depression, tropical rainforests created huge amounts of terrestrial and marine vertebrate fossils, where many mammals such as dinosaurs, ancestors of monkeys and large whales were previously found.
In 2016, Harith graduated from the Department of Zoology at the Faculty of Science at Alexandria University before she started to search for vertebrate fossils in 2018, specifically squamous reptiles in the Fayum area.
“I have always been fascinated by the life of animals, their behavior and the nature of their evolution. … I used to buy live snakes as pets, and I would even dissect them so I could see them turn into fossils,” she said.
After several arduous training and research trips to the Fayum area over the course of more than three years, Harith found one vertebra of the limbless lizard, along with seven vertebrae of snakes from the torso and tail regions, ranging in size from 2 millimeters (0.08 inches) to 1 centimeter (0.4 inches).
“Snakes decompose and turn into small fragments, so we rarely find a complete fossil of a snake,” Hares noted. “We were very surprised by the lizard’s sample, and it aroused suspicions because it was a first in Egypt. There are large protrusions in the vertebrae, and these protrusions are joined by large and strong muscles that enable the lizard to move easily in the absence of limbs."
She added, “By comparing the size of its vertebrae with the largest limbless lizards that live on Earth, we found out that the Egyptian Fayum lizard was the largest, with a vertebra length of 4 millimeters, while the vertebra of the largest lizard known today that currently lives in both Africa and Asia is 2 millimeters long.”
Asked about the samples of the snake vertebrae, Harith said that they belong to the great ancestor of modern snakes, which bear the name Procerophis, such as cobra and tarita. Other specimens of the snake belonged to the Renenutet, a snake named after the ancient Egyptian goddess of feeding and harvesting, who bore a cobra head.
Shorouk al-Ashqar, MUVP researcher who is in charge of excavations at Mansoura University, told Al-Monitor, “The discovery is very important because it includes fossils of reptiles that were rare to find in that time period on the African continent.”
She said, “Add to this that the discovery broke new ground in the formation of the map of animal migration in ancient times."
The JVP, which published the study, said that the discovery showed evidence of terrestrial animal exchange between Asia and North Africa during the early and mid-Eocene Epoch along the southern edge of the Tethys Sea, the ancient sea that separated the continents throughout different ages.
Harith went on to formulate a hypothesis whereby some squamous reptiles such as snakes are able to change their behavior and adapt to climate change, and that this is what helped them pull through the mass extinction wave that hit the Earth in the Cretaceous period, and helped them survive to this day.
The young researcher explained that snakes are smaller than extinct mammals such as dinosaurs, so they can hide in the event of environmental changes, even if such changes involved an ice age, and they can survive for long periods without food thanks to their muscle mass.
The Nature Communications journal revealed in a study published in September that all the nearly 4,000 snakes that are still alive to date are the product of the evolution of only six species of snakes — the ones that survived the mass extinction at the end of the Cretaceous period that killed the dinosaurs.
Ashqar concurred and said that snakes are very sensitive to climate changes, but they have proven ability to adapt to new environments.
However, she said that Fayum had a tropical rainy environment attractive to living organisms 37 million years ago, before changes occurred on the globe that led to the migration of other organisms such as lemmings and monkeys from Egypt to the tropics of South Africa and Asia.
"That's why this study prompts us to continue excavating the ancient Fayum area to unravel the mysteries of their [animals'] evolution over time,” Ashqar added.
Regarding her next step, Harith said that she will continue her work in deciphering the mystery of the legless lizard, how it came to Egypt and why it no longer lives in Egypt — while it continues to live in Asia and Africa.