Scientists and other researchers have examined some ancient fossils which were identified as the remains of a rather small monkey which is extinct.

These remains were found and brought back to the surface by divers from an underwater cave in the Dominican Republic.

The researchers who examined the fossils have come to the conclusion that the remains are somewhere in the neighborhood of 3,000 years old, but are saying that the species of monkey which these remains came from, could be much much older.

This sheds some light about the origin of primates in the region.

It may also suggest that many more ecologically valuable treasures could be unearthed beneath the sea, by the rather unusual field of study known as “underwater paleontology”

A researcher from the Brooklyn College in New York, Dr. Alfred Rosenburger, was in charge of the examination process of the tiny monkey’s bones, the results of this process were then published in the Royal Society journal Proceedings B.

Dr. Rosenburger has explained that the fossils which were incovered, including an almost complete skull, were discovered by a crack team of scuba divers who were spelunking in the underwater cave in the area.

“It’s miraculous that they even saw it,” he said, “When they discovered it, they were fearful the bones were exposed, so they moved the material to a little nook to protect it.”

Upon learning of he discovery Dr. Rosenburger went about getting official permission to take the fossil out of the cave, and then returned with the scuba divers October of last year to pick them up.

The bones were packed into tupperware containers, and then brought to the surface by the divers.

The famous Sharktooth Hill Bone Bed near Bakersfield has tantalized the imagination of scientists and laymen alike since it was first discovered in the 1850s. How did a six-to-20-inch-thick layer of fossil bones, gigantic shark teeth and turtle shells three times the size of today’s leatherbacks come to be?

Was this a killing ground for C. megalodon, a 40-foot long shark that roamed the seas until 1.5 million years ago? Perhaps a great catastrophe like a red tide or volcanic eruption led to animal mass-death in the region? Or is this simply the result of Sharktooth Hill being used as a breeding ground for generations of marine mammals throughout the millennia?

A research team consisting of palaeontologists from the United States and Canada are now offering their take on the Bone Bed, suggesting it is not the result of a sudden die-off or a certain predator. Instead, the North American team sees it as a 700,000-year record of normal life and death, kept free of sediment by unusual climatic conditions between 15 million and 16 million years ago.

The research team bases its hypothesis on a new and extensive study of the fossils and the geology of Sharktooth Hill. Roughly 3,000 fossilized bone and teeth specimens found in various museums, including the Natural History Museum of Los Angeles County (NHM) and UC Berkeley’s Museum of Paleontology (UCMP), have been scrutinized, and the researchers also cut out a meter-square section of the bone bed, complete with the rock layers above and below.

“If you look at the geology of this fossil bed, it’s not intuitive how it formed,” says Nicholas Pyenson, a former UC Berkeley graduate student who is now a post-doctoral fellow at the University of British Columbia. “We really put together all lines of evidence, with the fossil evidence being a big part of it, to obtain a snapshot of that period of time.”

The existence of a 700,000-year window through which we can catch a glimpse of the past is naturally magnificent news for anyone interested in evolution and Earth’s history.

When the Central Valley was a sea

When the Sharktooth Hill Bone Bed formed between 15,900,000 and 15,200,000 years ago, the climate was warming up, ice was melting and the sea level was much higher than today. What is today California’s Central Valley was an inland sea with the emerging Sierra Nevada as its shoreline.

After closely examining the geology of the Sharktooth Hill area, the research team was able to confirm that it had once been a submerged shelf inside a large embayment, directly opposite a wide opening to the sea.

Several feet of mudstone interlaced with shrimp burrows is present under the bone bed, which is typical of ocean floor sediment several hundred to several thousand feet below the surface. Inside the bone bed, most of the bones have separated joints, indicating that they have been scattered by currents.

“The bones look a bit rotten, as if they lay on the seafloor for a long time and were

abraded by water with sand in it“, says UC Berkeley integrative biology professor Jere Lipps.

Many bones also had manganese nodules and growths on them, something which can form when bones sit in sea water for a long time before they are covered by sediment. According to the team, the most likely explanation for this is that the bones have lain exposed on the ocean floor for 100,000 to 700,000 years while currents have carried sediment around the bone bed. The prevailing climatic conditions at the time have made it possible for the bones to accumulate in a big and shifting pile at the bottom of the sea.

“These animals were dying over the whole area, but no sediment deposition was going on, possibly related to rising sea levels that snuffed out silt and sand deposition or restricted it to the very near-shore environment,” says Pyenson. “Once sea level started going down, then more sediment began to erode from near shore.”

The team discards the breeding-ground hypothesis due to the scarcity of remains from young and juvenile animals. Hungry Megalodon sharks being the main contributors to the bone pile is also unlikely, since few bones bear any marks of shark bites. If the bone bed was the result of mass-death caused by an erupting volcano the absence of volcanic ash in the bed would be very difficult to explain, and the presence of land animals like horses and tapirs that must have washed out to sea make the red-tide hypothesis equally thin.

Amazing remains from the past

The Sharktooth Hill Bone Bed covers nearly 50 square miles just outside and northeast of Bakersfield in California and is one of the richest and most extensive marine deposits of bones in the world. Studied parts of the bone bed average 200 bones per square meter, most of them larger bones. Ten miles of the bed is exposed, and the uppermost part of the bed contains complete, articulated skeletons of whales and seals.

Within the bone bed, scientists have found bones from many species that are now extinct and the bed provides us with invaluable information about the evolutionary history of whales, seals, dolphins, and other marine mammals, as well as of turtles, seabirds and fish. Sharktooth Hill is naturally the sight of some impressive shark findings too, including shark teeth as big as a hand and weighing a pound each.

A small portion of the bone bed was added to the National Natural Landmark registry in 1976 but the rest is in dire need of protection.

A collaborative effort

The research team, who’s study will be published in the June 2009 issue of the journal

Geology, consisted of:

– UC Berkeley integrative biology professor Jere Lipps, who is also a faculty curator in UC Berkeley’s Museum of Paleontology.

– Nicholas Pyenson, a UC Berkeley Ph.D who is now a post-doctoral fellow at the University of British Columbia.

– Randall B. Irmis, a UC Berkeley Ph.D who is now an assistant professor of geology and geophysics at the University of Utah.

– Lawrence G. Barnes, Samuel A. McLeod, and Edward D. Mitchell Jr., three UC Berkeley Ph.D’s who are now with the Department of Vertebrate Paleontology at the Natural History Museum of Los Angeles County.

Researchers at Tokyo Institute of Technology have undertaken what is believed to be the very first CT scan of eggs inside a coelacanth fish.

“I was surprised to see that all the eggs were the same size,” said Dr Norihiro Okada, a bioscience professor at the university and a member of the research team. “I hope to do research into why this is.”

Each coelacanth fish was roughly 170 cm (67 in) long and weighed about 70 kg (154 lbs). After being captured off the coast of Tanzania, both fishes were frozen and send to Japan where the CT scan showed how each fish contained roughly 40 eggs; each egg being about 7 cm (almost 2 ¾ in) in diameter.

The eggs of a coelacanth are never released into the water because the offspring hatch while still inside their mother. The young fish sometimes reach a length of 30 cm (12 in) before leaving their mother’s body.

Coelacanths were long believed to have gone extinct around the same time as the dinosaurs, until scientists realized that these fishes actually turn up in the nets of African and Asian fishermen now and then. The first confirmed finding is from 1938 when a specimen was captured in the Indian Ocean.

Coelacanths are of special interest to evolutionary biologists since they are thought to represent an early step in the evolution of fish to amphibians. You can read more about this in our coelacanth article.

An expansion of vertical seagrass occurring some 25 million years ago was probably what prompted seahorses to evolve from horizontal swimmers to upright creatures. If you live in vertical seagrass, an upright position is ideal since it allows you to stay hidden among the vertical blades.

This new idea is put forward in a report by Professor Beheregaray* and Dr Teske** published in the journal Biology Letters on May 6.

Sea horse picture from our Seahorse section.

Only two known fossils of seahorse have been found and this scarcity of fossil records has made it difficult for scientists to determine when seahorses evolved to swim upright. The older of the two fossils is “just” 13 million years old and no links between the two fossils and horizontally-swimming fish has been found.

“When you look back in time, you don’t see intermediate seahorse-like fish,” Beheregaray explains. There are however fish alive today that look like horizontally-swimming seahorses and Beheregaray and Teske have therefore studied them in hope of finding clues as to when seahorses made the transition from horizontal to vertical swimming.

By comparing DNA from seahorses with DNA from other species of the same family, Beheregaray and Teske were able to determine who the closest living relative to seahorses was.

“The pygmy pipehorses are by far the most seahorse-like fish on earth, says Beheregaray. “They do look like the seahorses, but they swim horizontally“.

When you have two closely related species, you can use molecular dating techniques to calculate when the two species diverged from each other. Beheregaray and Teske used a molecular dating technique that relies on the accumulation of differences in the DNA between the two species, and then used the two existing fossils to calibrate the rate of evolution of DNA in their molecular clock. By doing so, the two researchers could conclude that the last common ancestor of seahorses and pygmy pipehorses lived around 25 to 28 million years ago. At this point, something must have happened that led to the formation of two distinct species, and Beheregaray and Teske believe that this “thing” was the expansion of seagrass in the habitat where seahorses first evolved.

The time in history when seahorses arose, the Oligocene epoch, coincided with the formation of vast areas of shallow water in Austalasia. These shallow waters became overgrown with seagrass and turned into the perfect habitat for upright swimming seahorses that could remain hidden from predators among the vertical blades. The pygmy pipehorse on the other hand lived in large algae on reefs and had no use for an upright position, hence it continued to swim horizontally just like their common ancestor.

“The two groups split in a period when there were conditions favouring that split,” says Beheregaray. “It’s like us. We started walking upright when we moved to the savannahs. On the other hand, the seahorses invaded the new vast areas of seagrass.”

* Associate Professor Luciano Beheregaray of Flinders University

http://www.flinders.edu.au

** Dr Peter Teske of Macquarie University

http://www.macquarie.edu.au

The discovery of three new species of fossilized octopi in Lebanon has caused scientists to suspect that the first octopus appeared tens of millions of years earlier than previously thought.

In a paper published in a recent issue of the journal Palaeontology, researchers Fuchs, Bracchi and Weis describes three new species of fossil octopus placed in two new genera: Keuppia and Styletoctopus. The species have been given the names Keuppia levante, Keuppia hyperbolaris and Styletocopus annae.

The descriptions are the result of the fortunate discovery of three astonishingly well preserved octopus fossils from the Cenomanian, i.e. octopus that lived at some point between 93 and 100 million years ago.

Studying the history of octopi is difficult since the octopus, unlike dinosaurs for instance, is composed almost entirely of soft tissue; predominantly muscle, skin and viscera. When an octopus dies the body rapidly decomposes and vanishes, and extraordinary conditions are necessary for the animal to leave any fossil record behind.

Fortunately for science such extraordinary conditions must have been at hand in Lebanon some 100 million years ago, because the three newfound fossils are so well preserved that even traces of muscles, suckers, internal gills and ink can be distinguished.

This type of fossil is so rare that Mark Purnell, for the Palaeontological Association, remarked that finding an octopus as a fossil “is about as unlikely as finding a fossil sneeze”.

Before these three species were discovered, only one species of fossil octopus was known to science.

For more information, see the paper published in Palaeontology: Fuchs, D, G Bracchi and R Weis (2009) New Octopods (Cephalopoda: Coleoidea) from the Late Cretaceous (Upper Cenomanian) of Hakel and Hadjoula, Lebanon. Palaeontology 52, pp. 65–81.

According to a new study from Uppsala University, the origin of fingers and toes can be traced back to a type of fish that inhabited the ocean 380 million years ago. This new finding has overturned the prevailing theory on how and when digits appeared, since it has long been assumed that the very first creatures to develop primitive fingers were the early tetrapods, air-breathing amphibians that evolved from lobed-finned fish during the Devonian period and crawled up onto land about 365 million years ago.

Lead author Catherine Boisvert[1] and co-author Per Ahlberg[2], both of Uppsala University in Sweden, used a hospital CT scanner to investigate a fish fossil still embedded in clay. “We could see the internal skeleton very clearly, and were able to model it without ever physically touching the specimen,” says Ahlberg. The scan revealed four finger-like stubby bones at the end of the fin skeleton. The bones were quite short and without joints, but it was still very clear that they were primitive fingers. “This was the key piece of the puzzle that confirms that rudimentary fingers were already present in the ancestors of tetrapods,” Catherine Boisvert explains.

The scanned fossil was that of a meter-long Panderichthys, a shallow-water fish from the Devonian period. Panderichthys is an “intermediary” species famous for exhibiting transitional features between lobe-finned fishes and early tetrapods, while still clearly being a fish and not a tetrapod. The specimen used was not a new finding; it had just never been examined with a CT scan before.

So, why have researchers for so long assumed that digits were something that evolved in tetrapods without being present in their fishy ancestors? The main reason is the Zebra fish (Danio rerio), a commonly used model organism when vertebrate development and gene function is studied. If you examine a Zebra fish, you will find that genes necessary for finger development aren’t present in this animal. Researchers therefore assumed that fingers first appeared in tetrapods and not in fish.

It should be noted that similar rudimentary fingers were found two years ago in a Tiktaalik, an extinct lobe-finned fish that lived during the same period as Panderichthys. Tiktaalik is however more similar to tetrapods than Panderichthys.

The Panderichthys study was published in Nature on September 21.

A 380 million-year-old pregnant fossil has been discovered by researchers from University of Western Australia. The fossil was unearthed in the Kimberleys and contains a 6 cm embryo with its umbilical cord intact. Mother and baby belong to an extinct species of shark-like fish that could be found in lakes and seas for almost 70 million years before it disappeared. This is the oldest example of a mother of any species giving birth to live young.

“This is also the first evidence of sex in vertebrates with jaws resulting in the oldest known example of a fish giving birth to live young rather than expelling a clutch of eggs,” says Dr Kate Trinajstic, Research Associate at the University of Western Australia, to News.com.au.

The fossilized species has been given the name Materpiscis attenboroughi. Mater is the Latin word for “mother” and piscis is the word for “fish”, so the genus name literary means mother-fish in Latin. The second part of the name, attenboroughi, is of course an homage to celebrated broadcaster and naturalist Sir David Attenborough. The fossilized fish belongs to the placoderm fishes, a group of fish commonly referred to as ’the dinosaurs of the seas’ since they dominated lakes and seas during the Middle Palaeozoic Era (c. 420 to 350 million years ago).

The fossil has now been given a new home at the Western Australian Museum.

Read the full story in Narelle Towie’s article at News.com.au. At this page, you can also see pictures of the fossil and drawings of what the fish might have looked like when it was still alive.

http://www.news.com.au/perthnow/story/0,21498,23772231-948,00.html?from=public_rss

The fossil find was published in the science journal Nature on May 29 this year.

A newly investigated 290 million year old fossil may be an evolutionary missing link in the amphibian family tree. The fossil was collected in Texas by a palaeontologist with the Smithsonian Institution in the mid-1990s. The fossil eventually ended up at the National Museum of Natural History in Washington, D.C., where it was re-discovered and investigated in 2004.

The new analysis of the fossil has been carried out by Jason Anderson, a comparative biologist at the University of Calgary, Canada. According to Anderson, the fossil has an overall amphibian look but with interesting archaic features. The animal resembles a salamander, but the tail is stubby and the ears are similar to the ears of a frog.

“So it’s kind of a frogamander, if you will,” Anderson sais to National Geographic News.

The fossilized species has been given the name Gerobatrachus hottoni. Until recently, scientists believed that frogs, salamanders and the wormlike caecilians all hailed from a common ancestor. Gerobatrachus hottoni suggests that frogs and salamanders are much more closely related to each other than to the caecilians.

Read more in Anne Casselman’s article for National Geographic News.

http://news.nationalgeographic.com/news/2008/05/080521-frog-fossil.html

The study of the fossil appears in this week’s (May 21^st 2008) issue of the journal Nature.