Paleontology

The discovery of exceptionally well-preserved, tiny fossil seeds dating back to the Early Cretaceous corroborates that flowering plants were small opportunistic colonizers at that time, according to a new study.

Angiosperms, or flowering plants, diversified during the Early Cretaceous, about 100 to 130 million years ago. Based on evidence from living and fossil plants, the earliest angiosperms are usually thought to have had small stature. New data from the fossil record presented here strongly support this notion, but also indicates key differences from modern flowering plants.

The small seed embryos -- less than 0.3 millimeters in size -- and their surrounding nutrient storage tissues in well-preserved seeds were found in eastern North America and Portugal. 


A "dinosaur" fossil originally discovered on Prince Edward Island has been shown to have steak knife-like teeth, and researchers from U of T Mississauga, Carleton University and the Royal Ontario Museum have changed its name to Dimetrodon borealis, marking the first occurrence of a Dimetrodon fossil in Canada. 
Fossils of Dimetrodon have now been found in the USA, Canada and Germany.


In the 19th century, Darwin’s most vocal scientific advocate was Thomas Henry Huxley, who is also remembered as a pioneer of the hypotheses that birds are living dinosaurs. He noticed several similarities of the skeleton of living birds and extinct dinosaurs, among them, a pointed portion of the anklebone projecting upwards onto the shank bone (aka drumstick).

This “ascending process” is well known to specialists as a unique trait of dinosaurs. However, until the late 20th century, many scientists were doubtful about the dinosaur-bird link. Some pointed out that the ascending process in most birds was a projection of the neighbouring heel bone, rather than the anklebone. If so, it would not be comparable, and would not support the dinosaur-bird link.

Just how bad was the bite of Tyrannosaurus rex? Pretty bad, because the feeding style and dietary preferences of dinosaurs was closely linked to how wide they could open their jaws and T. rex could open quite wide.

Using digital models and computer analyses, Dr. Stephan Lautenschlager from the University of Bristol  studied the muscle strain during jaw opening of three different theropod dinosaurs with different dietary habits. Theropods (from the Greek for "beast-footed") were a diverse group of two-legged dinosaurs that included the largest carnivores ever to walk the Earth.  


When the largest modern-day plant-eaters, elephants, are in an area, they devastate the vegetation, like has happened in a South African nature reserve. So 15,000 years ago, when the herbivores like the Columbian mammoth, mastodons and giant ground sloths were even larger, more numerous and more widely distributed, and there were no dentists with high-powered rifles to take them down, how did the landscape survive? 


For years, evolutionary biologists have wondered how ecosystems during the Pleistocene epoch survived despite the presence of many species of huge, hungry herbivores, such as mammoths, mastodons and giant ground sloths.

Observations on modern elephants suggest that large concentrations of those animals could have essentially destroyed the environment, but that wasn't the case.

A new paper argues that the ecosystem was effectively saved by predatory animals that helped keep the population of large herbivores in check. Their findings show that intense, violent attacks by packs of some of the world's largest carnivores -- including lions much larger than those of today and sabertooth cats -- went a long way toward shaping ecosystems during the Pleistocene epoch.


Were dinosaurs fast, aggressive hunters like those in the movie "Jurassic World", or did they have lower metabolic rates that made them more like today's alligators and crocodiles?

For 150 years, scientists have debated the nature of dinosaurs' body temperatures and how they influenced activity levels.

A new paper contends that some dinosaurs had the capacity to elevate their body temperatures using heat sources in the environment, such as the sun.


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  Credit: NSF 


Scientists describe a perinatal group of Saurolophus angustirostris, a giant hadrosaur dinosaur, all likely from the same nest, found at the Dragon's Tomb in Mongolia, in a new study.

The Dragon's Tomb is a location famous for finding Late Cretaceous dinosaur fossils in the Gobi Desert, Mongolia, the authors of this study described three or four perinatal specimens or "babies" and two associated eggshell fragments. The young dinosaurs were likely part of a nest originally located on a river sandbank, and the authors suggest they are likely Saurolophus angustirostris (meaning 'lizard crest'), a dinosaur that is known from multiple well-preserved complete skeletons.  


A 48 million year-old horse-like equoid fetus has been discovered at the Messel pit near Frankfurt, Germany according to a study in PLOS ONE

Jens Lorenz Franzen from Senckenberg Research Institute Frankfurt, Germany, and Naturhistorisches Museum Basel, Switzerland, and colleagues completed their investigation of the fetus from a 48 million year-old horse-like equoid uncovered near Frankfurt, Germany in 2000. They evaluated the bones and anatomy and used scanning electronic microscopy (SEM) and high-resolution micro-x-ray to describe the ~12.5 cm fetus.


From trilobites to tyrannosaurs, most fossils are of creatures with hard shells or bones. These materials don’t easily biodegrade and sediment has time to build up around them and turn them into a record of the creature that is still with us millions of years after it has died. Soft-bodied organisms like worms, on the other hand, decay rapidly and their fossil record is decidedly patchy.

In exceptional circumstances, however, their remains are preserved and sometimes in the most unusual places. With the right detective skills, palaeontologists can use such discoveries to open up whole new windows on the history of life on Earth. A recent discovery found in 50-million-year-old rocks from Antarctica has yielded a particularly incredible example: fossilised worm sperm.