But you must remember that "southern California" was not where it is today in the distant past. The Topanga Formation has clear tropical environments.

Also, all ab's start out tiny, how many whorles (an ~age) did this little guy have?

Originally posted by Dr.GH

But you must remember that "southern California" was not where it is today in the distant past. The Topanga Formation has clear tropical environments.

Also, all ab's start out tiny, how many whorles (an ~age) did this little guy have?

I searched for more information on this and couldn't find anything especially since the source didn't mention where the paper was published. Sorry.

Originally posted by rogue06

I searched for more information on this and couldn't find anything especially since the source didn't mention where the paper was published. Sorry.

I couldn't find it either. The funny thing is that I live and work in Orange County. We have a very minor exposure of the Topanga Formation in Silverado Canyon, but I have never worked in it.

The object that Mahlon Tuttle donated to the Sternberg Museum of Natural History wasn’t a load of crap like he suspected. Instead it turned out to be something more interesting and more valuable.

Tuttle had thought he had some fossilized feces, or coprolite, from a mosasaur, a large marine reptile, that was found on his land outside of Quinter, Kansas – a small town in the northwestern part of the state that is not quite 200 miles northwest of Wichita. That would be a fairly rare find in itself, but Mike Everhart, the adjunct curator of the museum believes it may be something else, something even rarer.

The object instead appears to be a “colonite,” the partially digested stomach contents of the mosasaur’s last meal which appears to contain both bird bones and the jaw of a fish. Such a find is invaluable in determining more about what these creatures ate.

The colonite was found along with a few mosasaur vertebrae, the size of which indicates the creature was approximately 15 to 18’ (4½ to 5½ meters) long. The remains of mosasaurs are not uncommon in Kansas, which was submerged under an inland sea during the Cretaceous, the time that the marine reptiles lived. This mosasaur may have been a juvenile since most are larger, with some species having been as large as 55’ (17 meters) long. They are thought to have been the dominate marine predator of their time (although pliosaurs may have given them a run for the money).

Tuttle’s land is frequently searched for fossils and many of the things found there have been donated to the Sternberg Museum of Natural History at Fort Hays State University (around 50 miles east of Quinter). Despite being “out in the middle of nowhere,” the Sternberg is a world-class museum which is probably best known for its “Fish-Within-A-Fish” fossil (a 14' Xiphactinus that ate a 6' Gillicus shortly before dying) from the Late Cretaceous.


Further Reading:

Fossil fun turns into fabulous find

There's yet another entry in the tetrapod transitional series:

The 365 million-year-old fossil skull, shoulders and part of the pelvis of the water-dweller, Ventastega curonica, were found in Latvia, researchers report in a study published in Thursday's issue of the journal Nature. Even though Ventastega is likely an evolutionary dead-end, the finding sheds new details on the evolutionary transition from fish to tetrapods. Tetrapods are animals with four limbs and include such descendants as amphibians, birds and mammals.

Scientists don't think four-legged creatures are directly evolved from Ventastega. It's more likely that in the family tree of tetrapods, Ventastega is an offshoot branch that eventually died off, not leading to the animals we now know, Ahlberg said.

"At the time there were a lot of creatures around of varying degrees of advancement," Ahlberg said. They all seem to have similar characteristics, so Ventastega's find is helpful for evolutionary biologists.

Ventastega is the most primitive of these transition animals, but there are older ones that are oddly more advanced, said Neil Shubin, professor of biology and anatomy at the University of Chicago, who was not part of the discovery team but helped find Tiktaalik, the fish that was one step earlier in evolution.

"It's sort of out of sequence in timing," Shubin said of Ventastega.

Uh-oh! You mean evolution didn't proceed smoothly toward a "goal" of four-legged land critters?!? It proceeded in fits and starts, with sidetracks and dead-ends? Goodness knows what might be made of that!

Originally posted by Steviepinhead

There's yet another entry in the tetrapod transitional series:


Uh-oh! You mean evolution didn't proceed smoothly toward a "goal" of four-legged land critters?!? It proceeded in fits and starts, with sidetracks and dead-ends? Goodness knows what might be made of that!

It seems that the majority of the critics of this aspect of the ToE think that it supports the old discredited notion that was popular back in the 19th and early 20th century called orthogenesis; the view that evolution proceeded in a steady uniform manner in straight lines, without any side branches. Some of its supporters even envisioned creatures were essentially evolving toward a goal (a literal target of evolution), motivated by some inner force. That evolution detractors still think this is how evolution is said to work it is really no surprise considering how they continue to quote-mine George G. Simpson’s criticism of this sort of thinking and blatantly cite it out of context in order to support the premise that he was attempting to discredit the fact that horse evolution is demonstrated in the fossil record.

As to Ventastega itself, here are a few provocative quotes from a couple other sources:

Fossil fills out water-land leap

"Ventastega fills the gap between Tiktaalik and the earliest land based mammals. All these changes in these creatures are not going in lockstep; it's a mosaic with different parts of animal evolving at different rates. Ventastega has acquired some of land-animal characteristics, but has not yet got some of the other ones”
[ProfessorPer Ahlberg]


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Fish Ancestors of Humans Surprisingly Diverse

The fishlike ancestors of humans and other land animals were a surprisingly diverse bunch, according to a new fossil reconstruction of the transitory species Ventastega curonica.

The aquatic creature, which lived during the late Devonian period about 365 million years ago, represented an evolutionary midpoint between Tiktaalik, one of the earliest fish to clamber onto land, and primitive four-legged land animals, or tetrapods.



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Closing The Gap Between Fish And Land Animals

New exquisitely preserved fossils from Latvia cast light on a key event in our own evolutionary history, when our ancestors left the water and ventured onto land. Swedish researchers Per Ahlberg and Henning Blom from Uppsala University have reconstructed parts of the animal and explain the transformation in the new issue of Nature.

It has long been known that the first backboned land animals or "tetrapods" - the ancestors of amphibians, reptiles, birds and mammals, including ourselves - evolved from a group of fishes about 370 million years ago during the Devonian period. However, even though scientists had discovered fossils of tetrapod-like fishes and fish-like tetrapods from this period, these were still rather different from each other and did not give a complete picture of the intermediate steps in the transition.

In 2006 the situation changed dramatically with the discovery of an almost perfectly intermediate fish-tetrapod, Tiktaalik, but even so a gap remained between this animal and the earliest true tetrapods (animals with limbs rather than paired fins). Now, new fossils of the extremely primitive tetrapod Ventastega from the Devonian of Latvia cast light on this key phase of the transition.


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Great find

Per Ahlberg will shortly be entertaining polite questions on the tetrapodal topic of his recent find right over here!

Nine years ago, while fossil hunting in a remote tributary of the Te Hoe River west of Mohaka in northern Hawkes Bay, New Zealand (which is on the east coast of the North Island), Dr. Joan Wiffen noticed what she described as a grey lump “about the size of a rugby ball” of sedimentary rock protruding from the stream’s bank. After a colleague broke it open Wiffen said that she “immediately saw a bone structure inside that looked different from the bone of a marine reptile.”

One of New Zealand's most successful fossil hunters, who is credited with discovering that country’s first dinosaur back in 1974, Dr. Wiffen took it home and removed the bone from its matrix of rock. She described it as “a fairly non-descript and incomplete bone. It is heavily eroded and that's because it must have been transported in a riverbed for some time before it was buried.” Wiffen took the fossil to Dr. Ralph Molnar of the Queensland Museum in Australia, and recognized dinosaur authority. Molnar identified it as a vertebrae from the tailbone of a Titanosaurid, but not exactly which type, or even whether it was from a juvenile or adult specimen, due to the fossil’s condition.

Titanosaurs were a globally widespread (especially in the southern continents) and diverse group of sauropod dinosaur that included some of the heaviest terrestrial animals ever, weighing up to 110 tons (50 tonnes) – and possibly much more. A large titanosaurid was over a 147’ (45 meters) long and approximately 33’ (10 meters) tall. The titanosaurs were the last major group of sauropods and were very successful, being the dominant terrestrial herbivore and apparently replacing the other sauropod groups which died out by the middle of the Cretaceous. The single tailbone of the New Zealand find permits only a rough estimate to be made of its owner’s size.

The fossil is the first evidence that titanosaurids roamed prehistoric New Zealand, which was very different 80 mya (what the bone is dated at) than it is now. It was approximately 3 million years after “Zealandia” (the New Zealand land mass) is thought to have split away from the supercontinent of Gondwanaland. It was a low lying and lacked any significant mountains, covered in thick rainforests. Zealandia was notably larger than modern New Zealand, approximately half the size of present day Australia before it slowly sank below the waves.



Further Reading:

Kiwi fossil hunter's very big find

Giant dinosaur fossil find in Hawke's Bay

Kiwi dinosaur fossil a titanic find

This isn't a report on a fossil find but a couple of questions, and this seems the best place to grab answers.

It's clear that the world was teeming with life before Adam ever walked the earth. Given average conditions (if there ever was such a thing) what percentage of once living organisms became fossilized? In ideal conditions what is the minimum time required for fossilization to take place?

I've heard a news report in this country that a coal bed could form in a million years. This seems a bit of a short timescale to me. Is it at all feasible?

Thanks in advance!

Originally posted by MooseOnTheLoose

This isn't a report on a fossil find but a couple of questions, and this seems the best place to grab answers.

It's clear that the world was teeming with life before Adam ever walked the earth. Given average conditions (if there ever was such a thing) what percentage of once living organisms became fossilized? In ideal conditions what is the minimum time required for fossilization to take place?

I've heard a news report in this country that a coal bed could form in a million years. This seems a bit of a short timescale to me. Is it at all feasible?

Thanks in advance!

Very little becomes fossilized and little of what does is ever discovered. As for how long it takes, different things take different times and it all depends on the conditions. A shark's tooth can fossilize in the ocean can fossilize in 10,000 years. Other things in other areas can take far longer. I'm not sure on how long it takes coal to form.

Thanks for your response!

Very little becomes fossilized and little of what does is ever discovered.

No doubt true, but we uncover more and more each year, and the subject remains as exciting as ever.

A shark's tooth can fossilize in the ocean can fossilize in 10,000 years.

Much less than I expected.

I'm not sure on how long it takes coal to form.

I'll explore this further.

Originally posted by MooseOnTheLoose

Thanks for your response!

Very little becomes fossilized and little of what does is ever discovered.

No doubt true, but we uncover more and more each year, and the subject remains as exciting as ever.

A shark's tooth can fossilize in the ocean can fossilize in 10,000 years.

Much less than I expected.

I'm not sure on how long it takes coal to form.

I'll explore this further.

The primary reason for more being found, including many of the recent exciting large finds is that more people are looking in more places. This is especially true in China. Further, some of them have been found due to a better understanding of how and where they lived, giving experts the ability to predict where something is most likely to be found. A great recent example of this was the discovery of Tiktaalik.

The discovery of a couple of ancient human mandibles (lower jaw bones) has stirred up some interest.

The first consists of a partial human mandible, complete with three teeth, that was unearthed in the Mala Balanica cave, in the Sicevo gorge near the city of Niš, in southern Serbia. It was found approximately 4 meters down or about 2 meters below a Neanderthal village in a linked cave making it the earliest evidence of humans in southeastern Europe.

The mandible is archaic and primitive, but human. According to Belgrade University archaeology professor Dusan Mihailović, who headed the team investigating the jaw, “It is a pre-Neanderthal jaw that we believe is between 130,000 to 250,000 years old.” The jaw could have belonged to a homo erectus, the first kind of human to walk upright, who appeared in Africa 1.8 mya and was the predecessor of both modern man, or homo sapiens, and Neanderthals.

The team was quite surprised to unearth the section of human mandible below the layers of the Neanderthal village complete with a hearth and stone and bone tools that had been found on earlier excavations. “We were looking for Neanderthals, but this is much better,” exclaimed University of Winnipeg anthropology professor Mirjana Roksandic, who was called in to help identify the jaw. Roksandic described herself as “jumping around the house” with excitement when she was first contacted.

Anthropologists believe that migrations from Africa, which was the birthplace of man, moved northwards into the Middle East and Asia and perhaps into Europe, possibly in reaction to changes in their environment. But until now there has been a dearth of solid evidence showing human movement between Africa and Asia into Europe during the Middle to Early Upper Pleistocene.

Figuring that if such migrations existed they almost certainly had to pass through the Balkan corridor, Mihailović’s team set to look in the region knowing that very little research has been carried out in that region of Europe.

Though still awaiting absolute dating, both Mihailović and Roksandic are confident that the mandible will be confirmed at being over 100,000 years old and with verification in hand, expect to get sufficient funding to properly excavated the site.

The second human mandible is a complete specimen from a Homo erectus that was discovered at the Thomas I quarry in Casablanca by a French-Moroccan team. While this was the second erectus mandible to be pulled out of the Thomas I quarry (the first was a chance discovery nearly 40 years ago), it is the first one that was properly excavated thus establishing its context.

Both of these Moroccan mandibles have very similar characteristics while they have definite morphological differences with Homo erectus mandibles found at a site at the Tighenif site in Algeria, dated to 700,000 B.C. The Casablanca discovery was from a layer below one in which three human premolars and an incisor were found that date from 500,000 B.C. and also awaits absolute dating.

The find supports the belief that the Thomas I quarry is one of the most important prehistoric sites for gaining a better understanding of the early settlement of northwestern Africa by early men, a possibly establish evidence defining Africa’s part in the first populating of southern Europe.



Further Reading:

Startling Discovery In The Balkans

Balkan caves, gorges were pre-Neanderthal haven

Ancient human jawbone city professor's dream find

Newcomer In Early Eurafrican Population?

“It is a pre-Neanderthal jaw that we believe is between 130,000 to 250,000 years old.” The jaw could have belonged to a homo erectus, the first kind of human to walk upright, who appeared in Africa 1.8 mya and was the predecessor of both modern man, or homo sapiens, and Neanderthals.

This has several gross errors as it is. Neandertals are known from "130,000 to 250,000 years" BP and earlier, and H. erectus was not the first human to walk upright. So if they are merely arguing from radiometric dates, or some stratigraphic correlation, they will need to do better by direct analysis of the fossil material- we know how to tell the diffence between H. Erectus, H. neandertalis, and H. sapiens. For that matter, what of hidelbergensis?

Originally posted by Dr.GH

This has several gross errors as it is. Neandertals are known from "130,000 to 250,000 years" BP and earlier, and H. erectus was not the first human to walk upright. So if they are merely arguing from radiometric dates, or some stratigraphic correlation, they will need to do better by direct analysis of the fossil material- we know how to tell the diffence between H. Erectus, H. neandertalis, and H. sapiens. For that matter, what of hidelbergensis?

I may be mistaken but Mihailović seems to have been referring to the mandible as having belonged to a “pre-Neanderthal” in the sense that it pre-dated the Neanderthals at the Mala Balanica cave site in which it was found. The jaw still needs more analysis including a more positive identification (Roksandic’s work seems very preliminary) and is awaiting absolute dating as well.

Don’t know if this actually constitutes an actual “fossil” find, but it seems to be a good place to mention it.

Recent analysis of minuscule traces of carbon trapped inside tiny slivers of diamond thought to have formed a few hundred million years after Earth came into being shows that the carbon is a type often associated with plants and bacteria. This, of course, suggests that life started on Earth over 500 million years earlier than previously thought.

Dr. Alexander Nemchin and a team from the Curtin University of Technology’s Department of Applied Geology in Western Australia examined carbon isotopes that were trapped inside 22 diamond and graphite inclusions that formed inside 18 tiny zircon crystals measuring only 0.3mm (0.0118”) across that had been unearthed in the Jack Hills region of Western Australia. The Jack Hills consists of a band of folded and metamorphosed supracrustal rocks from where the oldest dated material on Earth has been found. The diamonds have been dated at being between 4.2 and 4.4 byo (4200-4400 myo) and are considered the oldest diamonds in the world.

The results of the analysis demonstrated that the diamonds contained unusually high concentrations of a light form or isotope of carbon known as carbon-12. Plants prefer carbon-12 over the heavier carbon-13 when they extract carbon from the atmosphere causing the plants to exhibit a different ratio. And as Dr. Nemchin explains, “The most common way to form light carbon on the modern Earth is photosynthesis.” All of these points toward the carbon from Jack Hill being from organic life.

“The discovery challenges our fundamental understanding of processes active in the early history of the Earth. It suggests that life may well have appeared on Earth long before the period of heavy-meteorite bombardment believed by some to have initiated the emergence of life on Earth,” Dr Nemchin said.

If life began on Earth over 4.2 bya, this implies that it had to survive the incredible bombardment from outer space that the Earth went through around 3.8 bya (an onslaught thought to have been responsible for the formation of the Moon), or that life arose twice in Earth’s history: once prior to the bombardment and then again afterwards.

However, the team readily admits that the conclusion is not definitive. Writing in the July 3, 2008 issue of the journal Nature, the researchers caution that their results are not definitive proof of early life but do "not exclude" the possibility. “We're all a little skeptical,” said Dr Martin Whitehouse of the Swedish Museum of Natural History and one of the authors of the paper.

One possible explanation is that the carbon is a result of inorganic chemical reactions possibly involving carbon oxides. Proponents of this view point to the wide-range of values for the carbon isotopes that were detected in the inclusions, arguing that since photosynthesis produces a fairly constant value, this is evidence of a chemical reaction.

Another explanation suggested by Nemchin’s team is that the carbon was delivered from outer space by so-called "chondritic" meteorites, which also have a similar chemical signature.

But if these carbons were formed by inorganic means then this questions theories that depend upon the widely held assumption that light carbon means life. And if the diamond-embedded zircons are extraterrestrial in origin, then it calls into question nearly all the theories we have concerning the zircons, including the possibility of early Earth being cooler and more habitable than previously thought (based upon the crystals displaying evidence of having formed out of a low-temperature magma that had been in contact with water).

Another potential objection is one brought up by Professor Minik Rosing of the University of Copenhagen, which is the possibility that the diamonds could be contaminated, perhaps introduced during polishing of the zircons. “If you look at the photos that they present, you always see these diamonds sat in cracks and fissures and cavities,” Rosing elaborates. “If they were original features [you would] expect at least some to be embedded within the structure of the crystals.” I personally see this as the most likely explanation since it doesn’t overturn as many apple carts as the others potentially do.

Currently the oldest evidence for life was discovered by Rosing in a region in west Greenland known for its intensely folded rocks called the Isua Belt and thought to date back from 3.7 bya. Like the Jack Hills’ specimen, the chemical traces suggest the presence of photosynthetic life forms, but unlike them the traces are found in a complete sequence of rocks instead of just isolated crystals. The carbon isotopes on their own aren’t enough to qualify as a distinct biosignature.

The next oldest traces of life are the 3.5 byo stromatolites (made by photosynthetic algae) discovered in the Pilbara region of Western Australia. Most news accounts that state the Jack Hills discovery pushes the date for the earliest life back 700 million years are referring to these Australian stromatolites rather than the older traces detected in Greenland.


Further Reading:

Carbon specks push back origins of life

Diamonds hint at 'earliest life'

Simple Life Form May Have Existed 700 Million Years Earlier Than Previously Thought

Diamonds suggest life began earlier

Ancient diamonds trigger debate over earliest life on Earth

Ancient diamonds suggest creating life is easy