Mars Once boasted a Thicker Atmosphere Than Earth’s Today

Modern Mars has a minimal atmosphere

NASA/JPL/USGS

Mars’ atmosphere may have once been far thicker, providing a protective layer against the frequent asteroid impacts that destroyed other celestial bodies.

Our solar system began forming around 4 billion years ago, and by that time, Mars was nearly fully developed. The planet existed within a vast reservoir of hot gas and dust swirling around a youthful sun, known as the solar nebula, which some planets absorbed into their atmosphere. However, it was believed that as the solar nebula dissipated, Mars would lose this gas, resulting in a thinner atmosphere.

Recently, Sarah Jollett from Paris’ Collège de France and her team propose that Mars retained this gas for a longer period, forming a primordial atmosphere akin to a sustained soup.

Shortly after the nebula receded, it was believed that the orbits of significant planets like Jupiter and Saturn influenced each other, subsequently disturbing the paths of comets and asteroids that headed towards the inner solar system, impacting rocky planets. While chemical signatures of these impacts can be found on Earth, evidence on Mars remains limited.

“All terrestrial planets faced bombardments from comets during this time, and Mars was no exception, so we should observe remnants of this cometary assault on Mars,” Jollett stated at the Europlanet Science Congress held on September 11th in Helsinki, Finland.

Jollett and her colleagues suggest that the dense, hydrogen-rich atmosphere during this era may have diluted comet material that was available for absorption by Mars. By running simulations of the early solar system, they estimated the potential amount of material impacting Mars and compared it to the detectable quantity. They deduced that the original Martian atmosphere had a mass equivalent to 2.9 bars, around three times the atmospheric pressure we experience on the surface today.

However, this atmosphere dissipated relatively swiftly over about a million years, according to Raymond Pierre Hambart from Oxford University, who was not involved in the study. This loss primarily occurred before liquid water could come to the surface of Mars. The necessary clear atmospheric conditions, rich in carbon dioxide, were likely not present in that thick primordial atmosphere.

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Source: www.newscientist.com

Newly Discovered Mongolian Bird-like Dinosaurs boasted Strong, Robust Hands

Paleontologists have discovered a new species of Dromaeosaurus dinosaur from a nearly complete and unique skeleton found in Mongolia during the 2000s.



Reconstruction of Sri Lapax. Image credit: Connor Ashbridge / CC by 4.0.

This newly recognized dinosaur lived during the Campanian stage of the Cretaceous period, approximately 75 million years ago.

Based on various derived traits of the skull, vertebrae, and overall skeletal structure, this species can be classified within a group of bird-like theropods known as Dromaeosauridae.

It has been named Sri Lapax, marking it as the second species in this genus, following Sri Devi, which was identified in 2021.

“Dromaeosauridae represents a clade of small to medium-sized theropod dinosaurs that have been found in various Cretaceous deposits across North America, Asia, Europe, South America, and extending as far as Antarctica and Madagascar.”

“Remnants of feather-like structures, true pennaceous feathers, and gastrointestinal remains can be observed in well-preserved Dromaeosaurus specimens from the Lower Cretaceous period, such as Daurong Wanggi, Sinornithosaurus millenii, and Micro Raptor Zhaoianus.”

“Together with Troodontids, Dromaeosaurids are generally acknowledged as the closest modern relatives of birds.”

The nearly complete skeleton of Sri Lapax was discovered in the Djadochta Formation in Mongolia.

“This Dromaeosaurus specimen was illegally collected prior to 2010 and subsequently passed through private collections in Japan and the UK before being obtained by a French company,” noted paleontologist Eldonia.

“The precise location of the discovery remains unknown.”

“We plan to propose a tentative origin for it in the Mongolian Ukhaa Tolgod region based on documentation relating to the specimen.”



Holotype of Sri Lapax prior to preparations at the Royal Institute of Natural Sciences in Belgium in 2010. The arrows denote single femurs reconstructed using parts from both original femurs (which were separated during preparation). Image credit: Moutrille et al., doi: 10.1080/08912963.2025.2530148.

Sri Lapax exhibits a unique combination of vertebral and pelvic characteristics along with notably robust hands.

“One of the most distinctive features of Sri Lapax,” the researcher remarked.

“When adjusted for equal length, the phalangeal elements of the Pollex are about 150% more robust laterally compared to homologous elements in other Djadokhtan Dromaeosaurids, and these hands are stockier than those found in other known Dromaeosaurids.”

“We propose that frequent interactions with the Serratopsians, along with aggressive behaviors from those species, may have driven the development of more robust forelimbs and stockier hands in several Djadokhtan velociraptorines.”

“Assuming that Sri Lapax shared predatory habits with its close relative Velociraptor mongoliensis, the more robust construction of its hands suggests an adaptation for hunting larger and sturdier prey compared to typical Velociraptor diets.”

A study detailing this discovery was published online in the journal Historical Biology on July 13, 2025.

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Léa Moutrille et al. New bird-like dinosaurs from the Mongolian Upper Cretaceous period indicate niche diversification among belosirapthrins with particularly robust hands. Historical Biology published online on July 13th, 2025. doi:10.1080/08912963.2025.2530148

Source: www.sci.news

Majestic Triassic Reptiles Boasted Primitive Wings

Illustration of the Triassic reptile Mirasaura grauvogeli

Rick Stikkelorum

Reptiles from the central Triassic boasted an elaborate coat of arms made of feather-like filaments, appearing over 100 million years before the first feathered dinosaurs.

The findings include two fossils and a total of 80 skeletons and crested fossils, uncovered between the 1930s and 1970s by a private collector named Louis Grovogel in the Vosges mountains of northeastern France.

It wasn’t until 2018 that Stephen Speakman from the Stuttgart State Museum of Natural History and his team could examine the fossils.

They are now officially describing and naming it Mirasaura grauvogeli, with its impressive coat inspired by the Latin term for remarkable lizards.

Discovering such advanced skin structures in reptiles dating back 247 million years was quite unexpected, according to Spiekman.

“It is indeed a remarkably luxurious structure, larger than the entire body of the creature. The summit consisted of individual appendages that closely overlapped each other, resembling the feathers of a bird’s wing,” he notes.

While the appendages of M. grauvogeli share a feather-like appearance, they also exhibit significant distinctions. “In feathers, this differentiation occurs via a complex branching process that creates feather barbs, barbules, and hooks. However, such branching is absent in Mirasaura appendages,” Spiekman explains.

The most well-preserved specimen of M. grauvogeli measures less than 15 centimeters in length, although Spiekman suggests it is likely a juvenile based on certain skeletal features.

Fossils preserving the bony structure of Mirasaura grauvogeli

Stephen Speakman

One fossilized coat is three times the length of the best-preserved juvenile, suggesting that M. grauvogeli could grow substantially larger. Spiekman estimates adults might reach a size of 50 to 100 centimeters.

“The overall structure of Mirasaura indicates it was likely an agile climber, akin to a chameleon or a tree-dwelling mammal,” he explains.

John Long from Flinders University in Adelaide, Australia, who was not involved in the research, describes it as a “truly remarkable” prehistoric species.

“It illustrates that evolution was experimenting with creating wings using reptilian skin, albeit imperfectly,” says Long. “These grand decorations on its back would have served for signaling and visual interaction rather than flight.”

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Source: www.newscientist.com

The ancient creature boasted “goblin-like” teeth and a customizable tail.

Artistic reconstruction of Borguamondor

Karen Townsend

An extinct creature uncovered in North America offers fresh insights into the region’s life around 75 million years ago.

The creature has been described as “looking like a goblin jumping out of a rock,” according to Hank Woolley of the Los Angeles County Natural History Museum. This species, known as Monstaurus, is part of a group of reptiles that thrived during the late Cretaceous period. Woolley notes it could have been “around 3 to 4 feet from tail to tip.” “Best to stay away,” he warns.

Woolley named the species Borguamondor. The first part of the name derives from a Lord of the Rings character, while the second part is inspired by an invented Elvish word, referring to its bone armor — a trait shared with its relatives, modern Gira Monsters (Healoderma Sumpectum).

Remarkably preserved fossils were found in Utah two decades ago by Joseph Sertich. Initially, the Smithsonian Tropical Research Institute believed it was a prehistoric lizard. Sertich recalls, “I found a collection of scattered bones in a low, flat sandy area,” including the skull, vertebrae, jawbone, and parts of a hip bone.

Sertich encouraged Woolley to investigate the fossils at the museum in 2022. B. Amondor represents an extinct species of lizard known as the Monstaurus. They found evidence that some could shed their tails when injured, making it the oldest known example of this defensive strategy that modern lizards employ.

bones belonging to Borguamondor

Utah Natural History Museum/Bureau of Land Management

According to researchers, B. Amondor dined on small mammals, frogs, snakes, insects, and “things not primarily plants,” even considering dinosaur eggs as part of its “round-length” diet. Its habitat was likely a wetland ecosystem, quite hot and humid, resembling the modern-day U.S. Gulf Coast rather than the arid landscape we see today.

Randall Nydam from Midwest University in Illinois, though not involved in this research, emphasizes the cautionary aspect of the story, reflecting on the vulnerabilities of such formidable “monsters,” both ancient and modern. “We must also acknowledge that they are long gone,” he states, “vanished due to changing circumstances.”

Continuing the dialogue about B. Amondor, Sertich believes people should broaden their understanding of these creatures. “Imagining North America’s primal tropical forests should portray nightmare lizard-hunting dinosaurs navigating the underbrush and scaling trees,” he suggests.

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Source: www.newscientist.com