Monday, December 10, 2018

Ancient elephant-sized mammal ancestor gave dinosaurs a run for their money


An artist's reconstruction of Lisowicia bojani, an elephant-sized ancestor of mammals that lived during the Triassic


 This looks like the mother of all boars and likely crunched its way through a lot of opposition.

Our knowledge of mammalian evolution is speculative at best.  Accepted ideas merely mean no proof at all except that the originators are all dead.

The mammalian and reptilian exegesis appear to be separate enough but are they really?  The mammalian lineage is closer to our aquatic origins while the production of a shell is an unusual extra step by itself.  

Certainly the reptilian population made thing difficult for other forms of life.  Just how would we do today with the landscape filled with oversized hungry chickens?  This had a thick skin at least..

Ancient elephant-sized mammal ancestor gave dinosaurs a run for their money



An artist's reconstruction of Lisowicia bojani, an elephant-sized ancestor of mammals that lived during the Triassic(Credit: Dimitry Bogdanov/CC BY 3.0)

While mammals dominate the planet nowadays, for millions of years we played second fiddle to reptiles – most notably the dinosaurs. While reptiles became the biggest land animals to ever walk the Earth, mammals were mostly rat-sized critters running around underfoot. But now palaeontologists have described a mammal ancestor from the Triassic Period that bucked the trend and grew to the size of an elephant, giving those early dinosaurs a run for their money.
The newly-described species, named Lisowicia bojani, belonged to a group of animals called dicynodonts. Living about 250 to 220 million years ago during the Triassic, this herbivorous group has been described as "mammal-like reptiles," and would one day give rise to modern-day mammals.

An artist's recreation of the skeleton of Lisowicia bojani 


But Lisowicia is no ordinary dicynodont. While group members ran the size gamut from rat to ox, Lisowicia bojani trumped them all and stood as tall as an elephant, long before that was the norm. It measured 4.5 m (14.8 ft) long, 2.6 m (8.5 ft) high and weighed about nine tons, which the researchers say was around 40 percent bigger than the next-largest known dicynodont. That's also not far short of the biggest known Triassic dinosaurs.

But it wasn't just its size that made Lisowicia special – it lived about 210 to 205 million years ago, which is around 10 million years after most dicynodonts were thought to have died out.











The limb bones of Lisowicia bojani at the dig site in Poland
  

"Dicynodonts were amazingly successful animals in the Middle and Late Triassic," Grzegorz Niedzwiedzki, co-author of the study. "Lisowicia is the youngest dicynodont and the largest non-dinosaurian terrestrial tetrapod from the Triassic. It's natural to want to know how dicynodonts became so large. Lisowicia is hugely exciting because it blows holes in many of our classic ideas of Triassic 'mammal-like reptiles'."

The research was published in the journal Science.

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