Early Mammals Acted More Like Reptiles, Says Study

KEY POINTS

  • Scientists said early mammals led a less active but much longer lives
  • They analyzed teeth fossils of earliest mammals, the Morganucodon and Kuehneotherium
  • The study suggested that mammals developed some characteristics like warm-bloodedness at a later period

The first mammals that roamed the Earth millions of years ago functioned and acted more like reptiles even with their already advanced body structures, a new study showed. 

The research, published in Nature Communications, suggested there might be an overlap between warm-bloodedness and cold-bloodedness as mammals evolved in the past. It may be noted that mammals are considered as warm-blooded animals while reptiles are cold-blooded. 

As part of the study, a team of paleontologists analyzed teeth fossils from two of the earliest mammals, the Morganucodon and Kuehneotherium, which lived alongside early dinosaurs nearly 200 million years ago. This was the first time researchers used powerful X-rays to examine ancient fossils.

The

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Ancient tiny teeth reveal first mammals lived more like reptiles — ScienceDaily

Pioneering analysis of 200 million-year-old teeth belonging to the earliest mammals suggests they functioned like their cold-blooded counterparts — reptiles, leading less active but much longer lives.

The research, led by the University of Bristol, UK and University of Helsinki, Finland, published today in Nature Communications, is the first time palaeontologists have been able to study the physiologies of early fossil mammals directly, and turns on its head what was previously believed about our earliest ancestors.

Fossils of teeth, the size of a pinhead, from two of the earliest mammals, Morganucodon and Kuehneotherium, were scanned for the first time using powerful X-rays, shedding new light on the lifespan and evolution of these small mammals, which roamed the earth alongside early dinosaurs and were believed to be warm-blooded by many scientists. This allowed the team to study growth rings in their tooth sockets, deposited every year like tree rings, which

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New study reveals how reptiles divided up the spoils in ancient seas — ScienceDaily

While dinosaurs ruled the land in the Mesozoic, the oceans were filled by predators such as crocodiles and giant lizards, but also entirely extinct groups such as ichthyosaurs and plesiosaurs.

Now for the first time, researchers at the University of Bristol have modelled the changing ecologies of these great sea dragons.

Mesozoic oceans were unique in hosting diverse groups of fossil reptiles, many of them over 10 metres long.

These toothy monsters fed on a variety of fishes, molluscs, and even on each other. Yet most had disappeared by the end of the Cretaceous, 66 million years ago, when the dinosaurs also died out. There are still some marine crocodiles, snakes and turtles today, but sharks, seals, and whales took over these ecological roles.

In a new study, completed when she was studying for the MSc in Palaeobiology at the University of Bristol’s School of Earth Sciences, Jane Reeves, now

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Naked prehistoric monsters! Evidence that prehistoric flying reptiles probably had feathers refuted — ScienceDaily

The debate about when dinosaurs developed feathers has taken a new turn with a paper refuting earlier claims that feathers were also found on dinosaurs’ relatives, the flying reptiles called pterosaurs.

Pterosaur expert Dr David Unwin from the University of Leicester’s Centre for Palaeobiology Research, and Professor Dave Martill, of the University of Portsmouth have examined the evidence that these creatures had feathers and believe they were in fact bald

They have responded to a suggestion by a group of his colleagues led by Zixiao Yang that some pterosaur fossils show evidence of feather-like branching filaments, ‘protofeathers’, on the animal’s skin.

Dr Yang, from Nanjing University, and colleagues presented their argument in a 2018 paper in the journal Nature Ecology and Evolution. Now Unwin and Martill, have offered an alternative, non-feather explanation for the fossil evidence in the same journal.

While this may seem like academic minutiae, it actually

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Reptiles vulnerable to unscrupulous pet trading: study

Under-regulated pet trade leaves thousands of species vulnerable
Reptile in trade. Credit: Alice Hughes

More than a third of reptile species are bought and sold online in often-unregulated international trade, researchers said Tuesday, warning of the impact on wild populations of a pet market that puts a bounty on rare and newly discovered animals.


Even endangered species and those with small habitats—such as the speckled cape tortoise and Seychelles tiger chameleon—are bought and sold in online forums, according to the new study by researchers in Thailand and China, who found that three-quarters of trade is in species not covered by international regulation.

The market primarily caters to buyers in Europe and North America—the British Federation for Herpetologists has reported that there are more pet reptiles than dogs in Britain.

But unlike most other pets, the study found that 90 percent of traded reptile species and half of traded individuals are captured from the wild.

“We did not expect

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Evidence that prehistoric flying reptiles probably had feathers refuted

Naked prehistoric monsters! Evidence that prehistoric flying reptiles probably had
What did pterosaurs look like? Some researchers think they had a relatively smooth skin without any covering, similar in appearance to the skin on the palms of your hands. Others have argued that they were covered with small feather-like structures and looked a little bit like four-legged birds. Credit: Megan Jacobs, University of Portsmouth.

The debate about when dinosaurs developed feathers has taken a new turn with a paper refuting earlier claims that feathers were also found on dinosaurs’ relatives, the flying reptiles called pterosaurs.


Pterosaur expert Dr. David Unwin from the University of Leicester’s Centre for Palaeobiology Research, and Professor Dave Martill, of the University of Portsmouth have examined the evidence that these creatures had feathers and believe they were in fact bald

They have responded to a suggestion by a group of his colleagues led by Zixiao Yang that some pterosaur fossils show evidence of feather-like branching filaments,

Read More