Tag: Dinosaur Footprints

Paleontology News for December 2018.

There have been quite a few dino discoveries the past few weeks. I have four stories to cover so let’s get to it.

I’ll start with the discovery of a new species of ‘horned dinosaur’ formally known as a Ceratopsian and related to the well-known Triceratops. The new species, see image below, is named Crittendenceratops krzyzanowskii and is based on the re-evaluation of bones that were discovered almost 20 years ago in 73 million year old rocks southeast of Tucson Arizona. A team of researchers from the New Mexico Museum of Natural History and Science (NMMNH) carried out the re-examination finding “morphological features right away in the material of Crittendenceratops to establish a new species,” according to Sebastian Dalman the team leader.

Artists Impression of Crittendenceratops (Credit: Live Science)

According to the researchers, C krzyzanowskii was approximately 3-4 meters in length and likely weighted 700-800 kilos. The 73 million year age of Crittendenceratops puts it very close to the end Cretaceous period, making it probably one of the last species of ‘horned dinosaur’ to walk the Earth.

 

One of the big debates going on presently in the paleontological community concerns exactly when it was that the first feathers developed and how many different types of animals had them. Not too many years ago the very idea of a dinosaur having feathers would have been shocking. Now however it is well established that some dinosaurs worn feathers as insulation to help keep them warm. Perhaps even the mighty T rex himself was covered with a warm layer of fuzzy feathers.

Now an analysis of two fossils may push the origins of feathers back another 70 millions years and spread their occurrence to another entire group of extinct reptiles. A team of paleontologists from Nanjing University in China have found what they believe to be short, fuzzy, thread like structures on specimens of pterosaurs, the bat like flying reptiles that lived at the same time as the dinosaurs, but which were not dinosaurs. The fact that many of these thread like structures, see image below, split at their ends in a fashion similar to the development of feathers leads the researchers, lead by Professor Baoyu Jiang, to conclude that they are in fact the earliest fossil evidence of feathers.

Feathers on Pteranodon Fossils. Splitting at the ends indicates they are Feathers rather than Hair (Credit: Michael Benton / Nature Ecology and Evolution)
Pteranodon with Feathers (Credit: Yuan Zhang / Nature Ecology and Evolution)

The spread of feathers 70 million years further backward in time and to another entire group of extinct reptiles not only illustrates how wondrous the past history of life truly is, but also how piece by piece we are slowly uncovering it.

 

The very first dinosaur specimens to be scientifically described came from the United Kingdom. In fact the very word Dinosaur (Terrible Lizard) was coined by the British naturalist Sir Richard Owen. The paleontology of the UK has been studied for so long, and so thoroughly that you might think that there couldn’t be much left to discover. Erosion can often be a paleontologist’s friend however, revealing treasures that were hidden beneath layers of uninteresting rock.

This is what has happened in the Ashdown Formation in the English county of East Sussex. In the sandstone cliffs along the shore 85 dinosaur footprints have been recently discovered. Not only that but the prints are from as many as 13 different species, giving scientists a glimpse into what the quiet English countryside was like 100-140 million years ago. See image of a print below.

Theropod Dinosaur Footprint from Sussex UK (Credit: University of Cambridge)

The prints include many from well known dinosaurs, the Iguanodon, the Ankylosaurus, a possible Stegosaur as well as several Sauropods and Theropods (Basically that’s all of the dinosaurs you learned about when you were a kid!). Some of the prints are so well preserved that the texture of the animals skin can easily be seen, and therefore studied. See image below. Finds like these give paleontologists a wealth of information about the ecology of the ancient world, showing us how different, and yet how similar the world was so long ago.

Impressions of the Dinosaur’s Skin on Footprint (Credit: University of Cambridge)

 

My final story today may not be the most important scientifically but it is almost certainly the most spectacular. At least it has the coolest picture, see image below.

Artist’s Impression of a Shark attacking a Pteranodon (Credit: Mark Witton)

Researchers at the Los Angeles County Natural History Museum have been cleaning and preparing a well-preserved skeleton of a Pteranodon, a large species of those flying reptiles I mentioned above. As the researchers were cleaning the area of the fossil’s neck they noticed something stuck in between two vertebra, a shark’s tooth! See image below.

Shark’s Tooth, red arrow, Embedded in the neck of a Pteranodon Fossil (Credit: Stephanie Abramowicz, David Hone, Los Angeles County Natural History Museum)

Now the researchers do not believe that the shark, the tooth identifies it as a species known as Cretoxyrhina mantelli, leapt out of the water in order to attack the Pteranodon in mid flight. Rather they speculate that the flying reptile was floating on the surface of the ocean when the shark ambushed it from below. Even today sharks are known to attack seabirds in this manner, I’ve actually witnessed such an attack myself. So have sharks been feeding for millions of years off of flying animals who are foolish enough think that the ocean is a nice, quiet place to rest for a few minutes? By the way, this fossil Pteranodon was actually  discovered back in the 1960s. Another example of how a re-examination can make new finds.

The fossils found by the researchers in California give us a small window into a past event that is both dramatic and fascinating. With each such window we gain a better picture of the history of life on Earth.

Paleontology News for April 2018.

There have been several interesting new discoveries about ancient life over the past month and I think I’ll start in a place that doesn’t usually spring to mind when you talk about paleontology. Scotland.

Now trace fossils, or ichnofossils as they’re technically known, are not the actual remains of ancient animals but rather the remains of their activity. Trace fossils can be anything from a burrow to fossilized feces, called a coprolite. The image below shows the track made by a trilobite as it crawled along the seafloor.

Trilobite Track (Credit: Trilobite.info)

The best known type of trace fossils are of course Dinosaur Footprints! Well a recent discovery on the Isle of Skye in the Scottish Hebrides by paleontologists from the University of Edinburgh has brought to light more than fifty footprints from at least two different kinds of dinosaurs. The collection includes footprints from both a long necked, plant eating sauropod along with the two-legged meat-eating theropods. The image below shows one of the footprints for each of the sauropod and theropod.

Sauropod Footprint (Credit: New Your Times)
Theropod Footprint (Credit: The Guardian)

Back in the Jurassic period when the trace fossils were made the western islands of Scotland were a series of warm, shallow, soggy lagoons, a perfect place to leave footprints. By studying the footprints biologists can learn a great deal about the size, weight and even the gait of the animal that made them. The researchers estimate that the sauropod dinosaur measured two meters tall at its hip and was perhaps ten meters in length counting both its long neck and tail. They also believe that an early ancestor of the famous T-rex could have made the theropod tracks. The paleontologists hope to find more footprints on the Island and have even asked the local residents to keep a look out for them.

And speaking of carnivorous dinosaurs a new species has been identified from the Patagonia region of Argentina. Although the bones of Tratayenia rosalesi were unearthed a decade ago it is just recently that its discoverers, Doctors Domenica dos Santos and Ruben Juarez Valieri of the Museo de Ciencias Naturales in Argentina have identified it as a new species of a type of predatory dinosaur know as a Megaraptoridae.

Specimens of megaraptoridae have only been found so far in South America and Australia and they lived from the middle to late Cretaceous period. While Tratayenia rosalesi superficially resembles the famous T-rex (See image below) the skulls of megaraptoridae are longer and narrower and most importantly their arms are larger and much more powerful. (Remember how T-rex’s arms are such tiny, useless things.) I fact the megaraptoridae are probably more closely related to the velociraptor of the US southwest.

Tratayenia rosalesi (Credit: Andrew McAfee, Carnegie Museum of Natural History)

Only a few specimens of the megaraptoridae have been discovered so far and the researchers who found Tratayenia rosalesi hope it will tell us more about this interesting type of dinosaur.

My final story today doesn’t concern dinosaurs but rather is about their just as interesting contemporaries the Ichthyosaurs. The name ichthyosaur literally means ‘fish-lizard’ and indeed during the Triassic period a group of lizards returned to the sea and evolved into reptile versions of our modern porpoises and whales. Thousands of fossils of ichthyosaurs have been found and many different species have been described.

Now, the discovery of a bone from the lower jaw of a giant ichthyosaur from Gloucestershire in the UK has led a group of paleontologists to reevaluate other fossils from the same area that had been previously identified as ‘dinosaur vertebra’ but which may be other bones from a new species that could be the largest ichthyosaur yet discovered. The images below shows a typical, porpoise size ichthyosaur (by the way we do know that ichthyosaurs gave birth to live babies!) along with a complete fossil of one.

Artists representation of an Ichthyosaur (Credit: Gizmodo)
Ichthyosaur Fossil (Credit: The Fossil Forum)

The researchers, led by Dean R. Lomax of the University of Manchester, estimate that the animal to whom the fossil bones belonged might have been as long as 26 meters. If that estimate turns out to be accurate the ichthyosaur would have been approximately the same size as a blue whale, the largest animal alive today.