100 Million Year Old Spider Preserved In Amber As It Approached Its Victim

Spider Attack Preserved in Amber

Researchers from Oregon State University (college of science) have discovered a remarkable 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.

Famous Amber Fossil Site in Asia

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.

Social Behaviour in Arachnids

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.

Professor Emeritus of Zoology at Oregon State University, George Poiner Junior, a recognised authority on invertebrate fossils stated that the juvenile spider was attempting to pounce on the trapped, tiny parasitic wasp, but it never quite reached it. Both animals were covered in the tree resin before the spider could reach its victim.

Amazing Amber Fossils Found

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.

Wasp Being Attacked by Ancient Spider

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.

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The King of the Tyrant Lizards - What's in a Name?

How Did the Most Famous Dinosaur of All Get Its Name?

Tyrannosaurus rex is by far and away the most popular and famous dinosaur. When palaeontologists visit schools, this is the dinosaur they get asked about the most. We have been fortunate to work with a number of Tyrannosaur specimens and staff helped create some excellent fossils casts. It is great to see the way the children react when they get presented with their very own plaster cast of a Tyrannosaur tooth, one so well-preserved that the denticles (the individual saw-like serrations on the tooth) can still be seen and felt.

The Complicated Tyrannosaur Family Tree

However, the taxonomy of the Tyrannosauroidea family is in need of some revision. Most palaeontologists agree that the current classification of these meat-eating Theropods needs revising and the very name of Tyrannosaurus rex is indeed something of a misnomer.

Many people may be aware of the continuing debate amongst scientists about whether this large meat-eating dinosaur was primarily a scavenger or an active hunter. Tests carried out, estimating the bite force exerted at the tips of this large dinosaur's teeth, indicate a bite force in excess of 3,000 lbs per square inch, easily enough to shatter bone. There are a number of examples of crunched up Hadrosaur and Ceratopsid bones in the fossil record uncovered to date that are testament to the powerful jaws of a Tyrannosaur. However, whether, these fossils show feeding behaviour on a dead animal or indeed, the result of a Tyrannosaurus rex kill is very difficult to determine.

King of the Tyrant Lizards

The name Tyrannosaurus rex, such a well-known dinosaur, a name meaning "King of the Tyrant Lizards", very nearly did not get used. In scientific circles, the naming of a new species has to follow strict criteria. If there is any confusion over the naming of a specimen, perhaps a newly named species, after further research is discovered to be actually another example of an already named and described species, then the earliest name used should take precedence.

Edward Drinker Cope, the famous American palaeontologist described some newly discovered dinosaur bones in 1892. The honeycombed internal structure of the fossilised bones (called camellate) is diagnostic of Theropod and bird fossil vertebrae. Later Cope went onto name and describe a new dinosaur genus and species from these fossilised fragments. He called the new animal Monospondylus gigas (means "Giant Thin Vertebrae"). Scientists now know that these bones actually belonged to a Tyrannosaur.

When Henry Fairfield Osborn published his paper formally naming and describing T. rex in 1905 he actually published in the same report another formal description of what he believed at the time was another species of dinosaur. Osborn called this second dinosaur Dynamosaurus imperiosus (means "Imperial Power Lizard"). Some dermal armour had been found with this other fossil and Osborn assumed that the second, large meat-eating dinosaur described in this paper was covered in bony plates. It is likely some Ankylosaur or Nodosaurid remains had got mixed up with the Tyrannosaur bones when these animals were buried and this is how the confusion arose.

Dynamosaurus not Tyrannosaurus

The animal referred to as Dynamosaurus was actually discovered first but in the paper it was the later, second find, known as Tyrannosaurus rex that got described first. Only later when Fairfield Osborn reviewed his work did he realise that these animals (in fact all three of Barnum Brown's Tyrannosaur finds between 1900 and 1906), represented what was to be termed Tyrannosaurus rex. The rules of scientific nomenclature state that the name that should take precedence in such cases is the first name published. By a few lines of text, Tyrannosaurus rex was established in favour of Dynamosaurus.

Sold to the Natural History Museum

The first substantial fossil of the animal formerly known as Dynamosaurus but renamed T. rex representing a little over 10% of the actual skeleton and with skull material absent, was sold to the London Natural History museum in London. For a long, time these fossils were on display, the limited amount of actual fossil material supplemented by casts from other specimens and the creative use of a full size Tyrannosaurus rex illustration to help "flesh out" the exhibit. Some of the older palaeontologists can remember seeing it on display, although much of the Tyrannosaur material attributed to the Natural History museum is in storage.

The Story Continues

The story of Dynamosaurus does not end there. The very few fossils of Tyrannosaurs that scientists have do show morphological and anatomical differences. Could these be due to pathology, ontogeny or differences between the sexes? Maybe, or maybe not, could there really be several species represented by the Tyrannosaur remains excavated from Hell Creek and other late Cretaceous formations? Some scientists have suggested for example, that the name Dynamosaurus imperiosus be revived and used to describe the more robust forms discovered with the more gracile specimens being referred to as Tyrannosaurus rex.

No doubt the debate will continue...

Differences Reflected in Models of Prehistoric Animals

The uncertainty over Tyrannosaurus is reflected in the many subtle variants seen in scale model dinosaurs. Schleich of Germany, for example, introduced a model showing a "moving" Tyrannosaurus rex and then more recently introduced another version of T. rex depicted in the "Kangaroo-like" pose with the tail dragging on the floor. The introduction of this second model coincided with the 100th anniversary of the naming and describing of Tyrannosaurus rex in the paper published by Henry Fairfield Osborn.