Fossil snake with hind legs found in Argentina alters evolution timeline

A snake fossil approximately 100 million years old, discovered in the region of Patagônia, in Argentina, is providing unprecedented data on the evolutionary transition of these reptiles. The specimen, scientifically named Najash rionegrina, presents exceptional skull preservation and still has intact hind legs. The discovery challenges ancient concepts in biology. The finding shows that the loss of lower limbs occurred much more slowly than science previously estimated.

Pesquisadores of Universidade of Alberta, at Canadá, worked together with Argentine institutions to analyze the fossilized remains. The team used high-resolution scanning technologies to look inside the rock without causing damage to the historic material. The results indicate that the first snakes on the planet had robust bodies and large mouths. The study changes the perception about the habitat and feeding behavior of the ancestors of these animals during the Cretáceo period.

Tecnologia CT scan preserves material and reveals anatomy

The application of microcomputed tomography was fundamental to the success of paleontological research. The method allowed scientists to create three-dimensional models of the fossil’s internal structures. The rock encased delicate parts of the skull. Traditional mechanical extraction could destroy fragments essential for understanding the animal’s anatomy. X-ray technology has circumvented this problem. The researchers were able to visualize nerve pathways, blood vessels and the exact articulation of the bones in the head.

Durante After analyzing the images generated by the computer, the team noticed the presence of a jugal bone. Essa structure functions like the cheekbone in vertebrates. Modern snakes do not have this bone in their cranial formation. The presence of the jugal in rionegrin Najash indicates that the structure of the head of these reptiles underwent a simplification over millions of years. The ancient skull was more rigid and similar to that of land lizards.

The three-dimensional preservation of the skull offers answers to a mystery more than a century and a half old. Desde the first evolutionary studies, the anatomical transition between lizards and snakes generated heated debates in universities. The Argentine fossil fills an important gap in this timeline. Ele acts as an anatomical missing link. The images prove that adaptation to crawling did not require the immediate loss of complex facial bone structure.

Características physics of the species found in Argentina

Detailed analysis of the fossil revealed features that distance the species from previous theoretical models. The body structure of the prehistoric snake demonstrates a specific adaptation for hunting in surface environments. The animal did not present the physical limitations associated with strictly subterranean creatures.

The data collected by scientists highlights crucial points about the reptile’s morphology:

• The skull had strong joints and a wide mouth opening to capture larger prey.
• The hind legs were functional and maintained their biomechanical usefulness for a long period.
• The absence of front legs confirms that the reduction of limbs began at the front of the body.
• The structure of the spine indicates agility for movement on firm and uneven ground.
• The jugal bone connected the upper jaw, providing extra force for the bite.

Essas anatomical features show an efficient predator well adapted to its ecosystem. The presence of the hind legs was not just a useless vestige. The limbs helped to stabilize the body during movement and possibly at the time of mating. Evolution shaped the animal to take advantage of the advantages of crawling without giving up ancient physical tools.

Leia Também

South Korean developer confirms hardware requirements to run Crimson Desert on PC and consoles

Sony’s luxury device abandons the classic look and adopts a square module with an unprecedented red tone

Microsoft expands Xbox integration with communications app to justify subscriptions

The end of the theory of the blind and underground ancestor

Durante decades, the scientific community worked with the hypothesis that snakes evolved from small blind lizards that lived underground. Essa theory was based on the anatomy of some modern species of blind snakes, which have fused skulls and tiny mouths. The Patagônia fossil dismantles this narrative. Najash rionegrina had well-developed eyes and a mouth structure designed to swallow animals of considerable size.

Researcher Fernando Garberoglio, lead author of the study published in 2019, highlighted the importance of the discovery for evolutionary biology. The work included the collaboration of professor Michael Caldwell, Universidade and Alberta. The joint research established that the ancestors of modern snakes were surface creatures. Eles inhabited plains and forests, actively hunting in sunlight. Adaptation to underground life occurred much later in the lineage of some specific species.

The publication of the results in the scientific journal Science Advances had a great impact on zoology departments. The article details how the Najash lineage survived for tens of millions of years with its hybrid anatomy. The ecological success of the species proves that the long body shape with hind legs was highly functional. Nature did not eliminate limbs quickly. The transition was a process of fine-tuning to the environmental pressures of the period.

Formação Candeleros and the geological record of Patagônia

The location of the discovery adds an extra layer of relevance to the paleontological study. Formação Candeleros, located in Río Negro province, is one of the richest geological sites in América of Sul. The area preserves sediments from the beginning of Cretáceo Superior. The environment at the time was characterized by floodplains and ancient deserts. Climatic and geological conditions favored the rapid fossilization of animals that died in the region.

The preservation of articulated snake skeletons is an extremely rare event in paleontology. The bones of these animals are light and fragile. Geralmente, the remains are scattered by predators or destroyed by weathering before the fossilization process begins. The Najash rionegrina specimen was covered by fine sediment almost immediately after death. The rapid burial protected the three-dimensional structure of the skull and kept the hind leg bones in their original position.

Fieldwork at Argentina continues to reveal key pieces to the puzzle of vertebrate evolution. Canadian and South American Instituições maintain active partnerships to explore the region’s rocks. Cada new expedition searches for fragments that can further detail the fauna of Cretáceo. The study of Najash rionegrina sets a new standard of excellence for ancient reptile research. Understanding how snakes achieved their current shape helps science map the adaptation capacity of life in Terra.