Advanced Technology Clears up Blurry Amber Revealing Treasures Within

Researchers at the University of Manchester (England), have used advanced computer imaging techniques combined with three-dimensional X-ray scanning technology to reveal the face and details of an ancient spider that lived during the Palaeogene Period, some forty-nine million years ago.

Ancient Spider

The spider, known as a Huntsman Spider (Sparassidae), was preserved in tree resin that solidified and formed amber, trapping this little arthropod and enabling scientists nearly fifty million years later to study it in fine detail.  Amber is a sticky, resin produced by certain trees, especially conifers.  Insects and other organisms become trapped in this resin and fossilised when it hardens into amber.

Unfortunately, over time in the presence of oxygen the amber can become opaque, thus obscuring the tiny creatures that it might contain.  The use of sophisticated X-ray computer tomography enables scientists to lift the veil on the hidden treasures that amber might contain, enabling them to build up amazingly detailed pictures of pollen, plant debris and small creatures that were trapped and preserved.

This is not the first time that spider fossils have been revealed by close examination of amber.  Back in 2009 we reported on the discovery of the remains of spider’s silk threads being preserved in a lump of amber found in the UK that dated from the Cretaceous Period.

To read this article: World’s Oldest Spider’s Web Discovered.

Scientists from Manchester University, working with their colleagues from the Berlin Natural History Museum explored the amber nodule to reveal the facial features of this ancient spider.  Their work is being reported in the scientific journal “Naturwissenschaften”.  This team have demonstrated how opaque amber nodules can yield important scientific data, when X-ray computer tomography and other sophisticated research techniques are applied.

Commenting on the study, Dr David Penney, of Manchester University’s Faculty of Life Sciences stated:

“More than 1,000 species of fossil spider have been described, many of them from amber.  The best-known source is Baltic amber, which is about 49 million years old and that has been actively studied for more than 150 years.”

He went onto add:

“Indeed, some of the first fossil spiders to be described back in 1854 were from the historically significant collection of Georg Karl Berendt, which is held in the Berlin Natural History museum.  A problem here is that these old, historical amber pieces have reacted with oxygen over time and are now often dark or cracked, making it hard to see the animal specimens inside.”

The Manchester University team were surprised to find the oldest example known of a Huntsman spider preserved in amber.  These strong and quick spiders would have been unlikely candidates to get caught in slow moving tree resin – but apparently one spider forty-nine million years ago may have been unlucky enough to have been caught.  To test the theory that the spider’s remains were indeed that of a Huntsman, an international team of experts in the fields of fossils and living spiders, and in modern techniques of computer analysis decided to re-study Georg Berendt’s original specimen to determine what it was.

The Face of the Forty-Nine Million Year Old Huntsman

Picture credit: Manchester University

Dr Penny said:

“The results were surprising.  Computed tomography produced three-dimensional images and movies of astounding quality, which allowed us to compare the finest details of the amber fossil with similar-looking living spiders.  We were able to show that the fossil is unquestionably a Huntsman spider and belongs to a genus called Eusparassus, which lives in the tropics and also arid regions of southern Europe today, but evidently lived in central Europe fifty million years ago.”

Professor Philip Withers of  Manchester University concluded:

“Normally such fossils are really hard to detect because the contrast against the amber is low but with phase contrast imaging the spiders really jump out at you in three-dimensions.  Usually you have to go to a synchrotron X-ray facility to get good phase contrast, but we can get excellent phase contrast in the lab.  This is really exciting because it opens up the embedded fossil archive not just in ambers.”

For models and replicas of ancient invertebrates from the Palaeozoic and the Mesozoic: CollectA Prehistoric Life Models and Figures.

New Primate Genus Provides Evidence of Land Bridges between Old World and New

Texas, that vast state in the southern part of the United States may be synonymous with westerns, cattle and stetsons but forty-three million years ago the area was a tropical paradise, one of the last places in North America to suffer from global cooling as the world got drier and colder.  Flourishing in this verdant, tree covered world was a primate, an animal similar to a small, modern lemur in appearance.

A Primate

The fossil evidence was found in the Devil’s Graveyard area of the Badlands of western Texas, although not complete, remains of the jaw bone have been discovered providing an insight into the animal’s facial characteristics and diet.  The animal has been formally named Mescalerolemur horneri.

M. horneri lived during the Eocene Epoch about 43 million years ago.  It is a member of an extinct primate group –- the Adapiforms, that were found throughout the Northern Hemisphere in the Eocene.  However, just like Mahgarita stevensi, a younger fossil primate found in the same area in 1973, Mescalerolemur is more closely related to Eurasian and African Adapiforms than those from North America.

Mescalerolemur horneri

Chris Kirk, Associate Professor in the Dept. of Anthropology at the University of Texas commented:

“These Texas primates are unlike any other Eocene primate community that has ever been found in terms of the species that are represented.  The presence of both Mescalerolemur and Mahgarita, which are only found in the Big Bend region of Texas, comes after the more common Adapiforms from the Eocene of North America had already become extinct.  This is significant because it provides further evidence of faunal interchange between North America and East Asia during the Middle Eocene.”

By the end of the Eocene, primates and other tropically adapted species had all but disappeared from North America due to climatic cooling, so Kirk is sampling the last burst of diversity in North American primates.  With its lower latitudes and more equable climate, West Texas offered warm-adapted species a greater chance of survival after the cooling began, a sort of safe haven against the rigours of climate change.

Associate Professor Kirk stated that Marie Butcher, a then undergraduate who graduated with degrees in anthropology and biology from The University of Texas at Austin, found the first isolated tooth of Mescalerolemur in 2005.  Since that time, many more primate fossils have been recovered by Kirk and his team at a locality called “Purple Bench.”  This fossil locality is three to four million years older than the Devil’s Graveyard sediments that had previously produced Mahgarita stevensi.

Kirk stated:
“I initially thought that we had found a new, smaller species of Mahgarita.”

However, as more specimens were prepared at the Texas Memorial Museum’s Vertebrate Paleontology Lab, Kirk realised he had discovered not just a new species, but a new genus that was previously unknown to science.

Fossils of Mescalerolemur reveal it was a small primate, weighing only about 370 grams, less than an IPad. This body weight is similar to that of the living greater dwarf lemur.  Mescalerolemur’s dental anatomy reveals a close evolutionary relationship with Adapiform primates from Eurasia and Africa, including Darwinius masillae, a German fossil primate previously claimed (in a controversial paper) to be a human ancestor.

To read more about Darwinius: Debate over “Ida” Rumbles On.

However, the discovery of Mescalerolemur provides further evidence that Adapiform primates like Darwinius are more closely related to living lemurs and bush babies than they are to humans.

For example, the right and left halves of Mescalerolemur’s lower jaws were two separate bones with a joint along the mid-line, a common trait for lemurs and bush babies.  Mahgarita stevensi, the closest fossil relative of Mescalerolemur, had a completely fused jaw joint like that of humans.

For models and replicas of prehistoric mammals: Mojo Fun Prehistoric Life Models and Figures.

The pictures released shows Mescalerolemur horneri’s partial upper jaw (in two pieces, at left) and partial lower jaw (at right) (scales = 2 mm). Explaining the significance of the difference in jawbones, Kirk said:

“Because Mescalerolemur and Mahgarita are close relatives, fusion of the lower jaws in Mahgarita must have occurred independently from that observed in humans and their relatives, the monkeys and apes.”

The new genus is named after the Mescalero Apache, native Indians, who inhabited the Big Bend region of Texas from about 1700-1880.  The species name, horneri, honours Norman Horner, an entomologist and professor emeritus at Midwestern State University (MSU) in Wichita Falls, Texas.  Horner helped to establish MSU’s Dalquest Desert Research Site, where the new primate fossils were found.  The taxonomic relationship between the various types of Old World and New World Adapiforms suggest that faunal exchange was taking place over much of the Eocene Epoch, perhaps land bridges existed that permitted this exchange of genera.