“Mammoth of the Century” in Moscow for Study

The fossilised remains of a teenage Woolly Mammoth (Mammuthus primigenius) has begun to be examined by Moscow-based scientists after it was transported from the remote Siberian location where the fossilised carcase was discovered.  The late Summer months of August and early September are when a number of Woolly Mammoth and other Ice Age fossils are found in the northernmost parts of Russia.  The spring and summer rains coupled with the seasonally high temperatures permit parts of the permafrost to be thawed out or washed away by the erosion of river banks and this can expose the preserved remains of a number of long-dead prehistoric animals.

Woolly Mammoth Fossil

Some of the Woolly Mammoths have soft tissue preserved and with the publishing of the recent, controversial research into the half-life of DNA, talk inevitably turns to the possibility of obtaining genetic material from these extinct animals with the long-term aim of producing clones and resurrecting a species.

The Mammuthus genus (Mammoths) were members of the Elephantidae sub-family, taxonomically classified with extant elephants.  They were highly successful herbivores that lived across northern latitudes (Asia, Europe and North America) as well as Africa.  A number of species have been identified including the famous Woolly Mammoth (M. primigenius) and the larger species, associated with milder climates, the Columbian Mammoth (M. columbi).

The latest Woolly Mammoth fossil to emerge from the permafrost of northern Siberia was found by a young boy called Yevgeny Salinder, whilst he was walking along the banks of the Yenisei river about six weeks ago.  Mammoth fossils including tusks had been found in this area before, but it was not the sight of an over-sized, curved tusk that indicated to Yevgeny that he had found the remains of a Woolly Mammoth, but rather the smell the carcase gave off.  As the long-dead animal’s corpse is exposed to the air with the erosion of the matrix in which the fossil was buried, so the flesh begins to decompose once again.  It was the smell of putrefying flesh that alerted eleven-year old Yevgeny that a Mammoth’s body was lying nearby.

Models of Woolly Mammoths (CollectA Age of Dinosaurs Popular Models and Deluxe)

The CollectA Deluxe Woolly Mammoth model in 1:20 scale and the CollectA Prehistoric Life Woolly Mammoth calf. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

To view models and figures of Woolly Mammoths and other extinct animals: CollectA Deluxe – Figures and Models (Prehistoric Animals).

Exposing the Carcase

The back quarters and the legs were the parts of the carcase first exposed, local officials were contacted and the International Mammoth Committee alerted so that an excavation could begin to remove the Woolly Mammoth.  Scientists rushed out to the remote location and began the work of digging out the Mammoth remains.  Alexei Tikhonov, of the St. Petersburg-based Zoological Museum, and an expert of Siberian Mammoths was one of the scientists dispatched to excavate the carcase.  He has described this particular specimen as the best preserved and most complete Mammoth found in Russia for more than 100 years.

Nicknamed the “Mammoth of the Century”, the specimen is that of a teenage Woolly Mammoth, a male that died around 30,000 years ago.  Although the elephant’s trunk has rotted away, scientists have found samples of fur intact and one 1.5 metre long tusk, along with the remains of an eye and a small, Mammoth ear.  Mammoths had much smaller ear flaps than their modern elephant counterparts.  Small ears would not have lost as much heat as a large ear flap and there was no need for large ears to help cool the animal down, temperatures in this part of the world during the Pleistocene Epoch when this animal lived, would have rarely climbed into double figures (Celsius).

With the aid of local volunteers the Mammoth fossil was carefully excavated out of its Siberian grave, the process taking more than a week to complete.  Once the remains had been stabilised (kept at a constant, low temperature to preserve soft tissue), the fossil has been transported back to Moscow for detailed study.  Parts of the specimen will also be examined by Russian palaeontologists in St. Petersburg.

Preserving an Ancient Elephant

Spider Attack Preserved in Amber

Researchers from Oregon State University (College of Science) have discovered a remarkable, 100-million-year-old spider fossil showing the moment when an orb spider approached its victim ensnared in its web.  The fossil consists of the remains of the spider and a parasitic wasp, preserved in amber just as the spider was about to pounce upon the insect, as it was held fast by the silken threads of the spider’s web.  Amber is the hardened remains of sticky, often scented resin that is produced by certain types of trees as protection against damage to bark and in order to help protect against disease and fungal attacks.  Insects and other organisms can become trapped in the sticky resin as it flows down the trunk or branches and when fossilised and preserved as amber, these organic remains can be studied by scientists.

Trees first evolved the ability to produce resin of this nature in the Jurassic, but this piece of amber, discovered in the Hukawng Valley (also known as the Hukaung Valley), in northern Burma dates from the later Cretaceous geological period.

100-million-year-old Spider Fossil

The Hukaung Valley has been mined for amber and gold for many years, it has already produced a number of amber fossils containing insect remains.   About ten years ago, the fossilised remains of the world’s oldest bee was discovered in an amber nodule from a mine in the Hukaung Valley.  However, this is the first discovery of a predator/prey interaction concerning a spider and an insect trapped in a web.  The amber nodule containing the fossilised remains has been dated to approximately 97-100 million years ago (Albian faunal stage of the Cretaceous) – a time when the dinosaurs ruled the Earth.

In addition to the first spider, the silk and the remains of the spider’s attempted meal, the wasp, the amber nodule also contained the remains of a second male spider.  Scientists at the Oregon State University have interpreted this as evidence of social behaviour amongst arachnids.  Most extant species of spider are solitary hunters, often they are cannibalistic towards their own kind, mature males and females will attack immature members of their own species.  A number of species today show signs of social behaviour, living in colonies or aggregations.

The Oregon based team postulate that this fossil is evidence of such social, colonial activity in spiders back in the Cretaceous, the first evidence found of tolerance of other members of their own species by a spider.

The Spider About to Attack the Parasitic Wasp

100-million-year-old spider and wasp fossil.

Picture credit: Oregon State University.

Professor Emeritus of Zoology at Oregon State University, George Poiner Junior, a recognised authority on invertebrate fossils stated that:

“This juvenile spider was going to make a meal out of a tiny parasitic wasp, but never quite got to it.  This was a male wasp that suddenly found itself trapped in a spider web.  This was the wasp’s worst nightmare, and it never ended. The wasp was watching the spider just as it was about to be attacked, when tree resin flowed over and captured both of them.”

Over recent years, palaeontologists have discovered some amazing fossil specimens preserved in amber, from ancient Arthropods, to numerous types of insect, pollen, plant debris, even a frog, hairs from mammal and feathers from either an ancient bird or a dinosaur.  Such fossils provide an insight into deep time, a micro world which helps scientists to understand more about ecosystems and habitats.

To read about the discovery of ancient spider silk: World’s Oldest Spiders Web Discovered Entombed in Amber.

To read an article about feathers preserved in amber: Canadian Palaeontologists in a Flap over Feathers.

The wasp has been identified as an ancestor of today’s parasitic wasps that attack and disable spiders and insects and lay their own eggs into the paralysed body of their victim or instead, parasitise the eggs of such creatures.  The kind of spider preserved in the amber, a relative of today’s tropical orb spiders, but a member of an extinct genus would probably have been the sort of creature the wasp would have liked to attack.

As the research team members have stated in their press conferences, this fossil preserves the moment when a spider was able to turn the tables on a parasitic wasp.  There were at least fifteen silken threads preserved in the amber nodule, evidence of the spider’s web.  Some of these threads had trapped the wasp.

Both the spider and the wasp are scientifically described in an academic paper published in the journal “Historical Biology”.

For models and replicas of ancient invertebrates: CollectA Age of Dinosaurs Models (Popular).

Research into Hadrosaur Dentition Provides Clue to the Group’s Success

One of the most successful groups of large, land animals known to science are the Hadrosauridae, a group of ornithischian (bird-hipped), plant-eating dinosaurs that evolved from the iguanodontids during the Cretaceous geological period.  These animals evolved into many families and genera, some species grew up to twelve metres in length or more and they dominated terrestrial ecosystems across the Northern Hemisphere up until the demise of the Dinosauria 66 million years ago.  A new study examining the dentition of hadrosaurs, suggests their teeth were one of the reasons for their evolutionary success.

Dentition of Hadrosaurs

This type of dinosaur, commonly called “duck-billed” dinosaurs as they all had horny beaks is classified into two major taxons – the Lambeosaurinae and the Hadrosaurinae.  Lambeosaurs, dinosaurs such as Parasaurolophus, Corythosaurus and Olorotitan had hollow, ornate head crests.  The Hadrosaurinae, animals such as Gryposaurus, Maiasaura and Edmontosaurus lacked the often flamboyant crest.  Instead, these dinosaurs had flat, crestless heads or their snouts were ornamented with bony lumps or solid crests.

Taxonomic Relationships in the Hadrosauridae

Diversifying ornithischian dinosaurs.

Picture credit: Everything Dinosaur

Differences Between the Clades

There are other differences between these two clades of dinosaurs.  For example, the Hadrosaurinae generally had broader jaws and wider beaks than their Lambeosaurinae cousins.  This suggests different feeding habits with the narrow-beaked lambeosaurs being more selective feeders.  Both types of hadrosaur had many hundreds of closely packed, diamond shaped teeth in their jaws, some specimens had over 1,400 individual teeth in their mouths.  These teeth formed a “dental battery”, interlocked teeth to form a very efficient grinding surface to help these animals tackle tough plant material.  The upper and lower tooth batteries were angled so that when the mouth was closed the teeth formed a natural grinding surface.   For many years palaeontologists had known that these animals were very efficient processors of plant food, perhaps a clue to this groups’s success but new research proposes that the structure of the teeth themselves made these dinosaurs much more effective consumers of plants than most of today’s grazers.

To view models and replicas of hadrosaurs (lambeosaurines and Saurolophinae): Ornithischian Dinosaur Models (Safari Ltd).

Super Efficient Plant-Eaters

A typical crested hadrosaur (Lambeosaurinae).

Picture credit: Everything Dinosaur

A team of American scientists led by biologist Gregory Erickson of Florida State University (Tallahassee), have been testing the grinding capabilities of eighty-five-million-year-old duck-billed dinosaur teeth and examining their internal structure.  Their research shows that the hadrosaurs evolved extremely sophisticated teeth, more sophisticated than modern mammalian herbivores such as bison, horses and elephants.

Using teeth supplied by the American Museum of Natural History (New York), the research team created models of the jaws of these types of dinosaurs and subjected the teeth to diamond abrasion to simulate wear on the tooth surface as a result of grinding up plant material.  The teeth were then examined under light and electron microscopes and the degree of wear calculated.

Hadrosaur Dentition

These teeth were made for grinding.

Picture credit: D. Gregory Erickson

The study demonstrates that unlike most mammalian molars and pre-molars which are composed of four major tissues that wear at different rates, creating coarse, roughened surfaces to help break down tough plants, the duck-bills evolved a six tissue dental composition which improved the teeth’s ability to grind up food.

Tough, strong teeth designed to tackle plants has evolved repeatedly in the ungulates and other mammal groups.  However, a similar innovation in dental complexity occurred much earlier in the history of life on Earth, with the hadrosaurs.  Most reptilian teeth are not as complex, it seems that as the iguanodontids gave rise to the hadrosaurs so the teeth of these animals evolved into extremely efficient grinders.  The external layer of enamel being supported by layers of other tissue such as dentine.  Importantly, the researchers also discovered that the way tissues were distributed varied substantially within each individual tooth.   Each tooth in the dental battery would assume a different function as the morphology and the grinding surface of the tooth changed as it became worn.   Different surfaces would be exposed as the teeth migrated across the grinding and chewing surface of the jaw, before eventually falling out to be replaced with new teeth that emerged from the jawline.

The morphology and structure of the teeth would have enabled these herbivores to grind up tough plants such as horsetails, ferns, conifer needles and the newly evolved flowering plants.  Most reptiles have much more simple teeth structures and the scientists are not sure how such dentition evolved.  The lack of transitional fossils between iguanodontids and hadrosaurs is hindering the team’s progress as they search for answers in the fossil record.

Referring to hadrosaurs as “walking pulp mills“, Gregory Erickson and his research colleagues have declared the duck-billed teeth lined jaws as one of the most sophisticated grazing and grinding mechanisms ever to evolve in terrestrial mega herbivores.  Their teeth are more complex and better adapted to grinding than most of the large plant-eating mammals found today.