The Earth Story

Sinking Sauropods?

Diplodocus skeletons, such as this one from the Carnegie Museum of Natural History, Pittsburgh, grace Natural History Museums throughout the globe. When staring up at them, one can only wonder at their colossal size and bizarre long neck. But have you ever thought about the most important question concerning these giants of the Mesozoic world: would they float? A computational model, which makes assumptions on the muscle and bone densities of sauropods, has shown that, because sauropods have a pneumatised skeleton (it is hollow, much like a bird skeleton) rather than wading through deep lakes and rivers with only their necks exposed, they would have indeed begun to float.

But, before I let your imaginations run wild with thoughts of Camerasaurus freely floating downstream without a care in the world, I must warn you that the same research also showed that far from being care-free sailors, sauropods would have been unstable. They would most probably have ended up floating helplessly on their sides: a consequence of their centre of buoyancy being below their centre of mass.

So: could they float? Yes. Could they float well? Maybe not.

Sedg

Image credit: http://en.wikipedia.org/wiki/File:CM_Diplodocus.jpg

Original paper: Henderson, 2004: http://rspb.royalsocietypublishing.org/content/271/Suppl_4/S180.full.pdf+html

World’s longest known Sauropod Track

These photos show a 155 meter long dinosaur track found in Plagne, found today in the Jura mountains of France. During the Jurassic, 155 million years ago, this part of what is today central Europe was a tidal flat, where waters of the Tethys Ocean flowed up onto the continent and inundated lowlands in-between higher continental massifs. The Jurassic rocks of this area have been found to contain hundreds of dinosaur tracks, with quarries of them running through France and Switzerland. The dinosaurs walked in muddy soil along the edge of the Ocean and when the tide came in, those tracks were buried and eventually fossilized.

This particular site was discovered in 2009. Excavation, as seen in the second photo, took over 3 years and 2700 human-days of work. 134 distinct prints were unearthed in this trail, produced by the dinosaur Brontopodus plagnensis. Local authorities have established a park at this site.

-JBB

Image credit and original paper: [http://bit.ly/2nwnWNF]

Reference: [http://www2.cnrs.fr/en/3023.htm]

Let’s finish with the sauropods, some of the largest land animals ever. The upper photo here is a sauropod vertebrae. It’s the size of a single human. The next 2 images show sauropod growth - a small bone in a baby, followed by intermediate and fully grown leg bones. As with the other animals, researchers at the museum have used modern microscopic techniques on these bones to establish that they’re fully grown and how old the organisms were - by the time they were about 20, they were fully grown and practically football field sized.

the final image is a death assemblage. A number of bones of juvenile diplodocus were found encased in mud - far more than you’d ever expect to find in one spot. The dinosaurs probably got stuck in mud and were trapped there until they died. Some of them even show bite marks.

Real Life Jurassic Park?

Many of us have seen the Spielberg’s Jurassic Park and wondered if it was possible to bring the ancient creatures back to life just as the scientists did in the film. Not to worry, these Jurassic beings will not be roaming the streets anytime soon. However, a team of scientists led by Robert Reisz (University of Toronto Mississauga) have made a huge discovery – Jurassic dinosaur embryos.

Previously all dinosaur embryos have been dated to the Cretaceous period, making the samples unearthed by Reisz’s team 125 million years older than the oldest known samples! The team, comprised of scientists from Canada, Taiwan, China, Australia, and Germany, analyzed over 200 embryonic bones samples from different stages of the dinosaur’s development. This is the first time scientists are able to trace embryo growth through different developmental stages.

The samples represented approximately twenty different long-necked dinosaurs known as sauropodomorph Lufengosaurus – the most common early Jurassic dinosaur. The embryos came from multiple nests and showed various different stages of development. Typically dinosaur embryos are not found in such large quantities and have previously only provided a developmental snapshot compared to the latest findings.

Reisz and his team concentrated on the femur; being the largest bone, it is easily identifiable and shows consistent rapid growth, doubling in length across the samples. This rate of growth shows these dinosaurs experienced a very short incubation period.

The image seen here is a cross section of an embryonic femur. A lambda filter was used to enhance visualization resulting in the purple color. The outer honeycomb is embryonic bone tissue, the large spacing allows for blood vessels and osteoblasts (cells responsible for creating bone). The central medullary cavity is crystalized from the fossilization process.

The samples collected indicated the femurs were being constantly reshaped within the egg; this means the dinosaur’s muscles played a key role in bone development. These results are the first real proof that dinosaurs, like birds, moved while inside the egg.

Taiwanese members of Reisz’s team discovered organic material inside the embryonic bones. The researchers were able to use specifically targeted infrared spectroscopy to conduct chemical analysis on the femur bones. The analysis showed evidence of possible collagen fibers. Collagen is a protein typically found in bones. During the fossilization process bones are turned to rock so collagen fiber remnant is a huge discovery!

Only about one square meter of “dinosaur nesting grounds” has been unearthed so far and is a rare find the in fossil world. This treasure trove of dinosaur embryos also contains bits of eggshell – the oldest known eggshell for any terrestrial vertebrate! These dinosaur eggshells are only about 100 microns thick and are the most well-preserved to-date. With these new discoveries we will be able to have a more in-depth look into the dinosaur development process.

-ALT

Source: http://phys.org/news/2013-04-world-oldest-dinosaur-embryo-bonebed.html

Image Credit: University of Toronto

Australovenator wintonensis

Australovenator wintonensis (Winton’s southern hunter) is the most complete carnivorous dinosaur recovered from Australia. Fondly referred to as “Banjo” after the Australian bush poet, Andrew Barton Paterson, this theropod dinosaur weighed half a ton and was approximately 1.6m tall at the hip. From nose to tail Australovenator was approximately 5-6m long. The species was described from isolated ribs, gastralia, both dentaries and nearly complete forelimbs and hind limbs.

Unlike other theropods, such as Tyrannosaurus Rex, Australovenator’s muscular arms, armed with three large hooked claws on each hand, were frequently used during hunting. In addition to lethal claws, the jaw preserves fifteen serrated teeth found in situ, at various stages of emergence, with a second row of teeth within the jaw, as determined from CT scans. The bones from this specimen indicate a lightweight and extremely agile predator capable of reaching speeds of up to 30km/ hour.

The bones of Australovenator wintonensis were found alongside two other species of dinosaur, Diamantinasaurus matildae and Wintonotitan wattsi, both members of the infraorder Sauropoda. All three dinosaurs were found in what has been interpreted as an ancient billabong from the Cretaceous, approximately 98-95 million years ago.

AHP

Sources http://bit.ly/1SnXwUi http://dailym.ai/1Y1l05w http://bit.ly/1TjGXxq http://bit.ly/21UnrIi http://bit.ly/1RM1ANi http://bit.ly/1iYVwQh

Image: copyright Australian Age of Dinosaurs Museum

Scotland’s Sauropods

Over 170 million years ago, on what is now the northern Scottish island of Skye, Sauropods, some of the largest land animals on Earth walked through shallow coastal lagoon as indicated by several overprinting footprints. The new discovery makes the island of Skye the largest dinosaur site in Scotland and fills an important evolutionary gap in the history of these long-necked animals, which were some of the biggest of the dinosaurs.

Palaeontologists at the University of Edinburgh first identified the tracks in sedimentary rock, representative of a shallow, salt water lagoon environment. The footprints, some which are 70cm in diameter, form part of a larger trackway and are the first sauropod tracks found in Scotland. Until now, the only sauropod fossil material in Scotland came from a few teeth fragments and bone. The tracks have been discovered in multiple rock layers, middle Jurassic in age, suggesting they were left by many dinosaurs over a period of time.

As with any type of ichnofossil (trace fossil) it’s difficult to work out which species of Sauropod dinosaur was responsible for these tracks without any other fossil material. However, the researchers hypothesize they were produced by the distant relatives of a more well-documented species, Diplodocus. Furthermore, it’s estimated that these Sauropods weighed 10 tonnes and were at least 15 metres long. Tracks of are good indications of behavioural ecology, and in this instance clearly indicate these terrestrial dinosaurs waded into coastal lagoons (as was previously assumed).

AHP

Sources http://bit.ly/1NriZgH http://bit.ly/1TrVeWz http://bit.ly/1TrJtiH http://bbc.in/1Iq7F44

Image http://n.pr/1HEwYiD

A Prehistoric Discovery

Big things are happening in Spain; very big things. Researchers from the Miquel Crusafont Catalan Paleontology Institute have recently discovered hundreds of new fossilized dinosaur eggs and eggshells at the Coll de Nargo site in Lleida, Spain. After digging through many layers of strata, the team of paleontologists dug up eggs of sauropods, which are among some of the largest animals to ever roam planet Earth. Sauropods were herbivores with extremely long necks and tails that grazed the foliage of trees and shrubbery before becoming extinct some 65 million years ago.

The team was led by Albert García Sellés who explained that in addition to finding hundreds of untouched fossilized eggs, four new species that were previously unknown to the area were also discovered including Cairanoolithus roussetensis, Megaloolithus aureliensis, Megaloolithus siruguei, and Megaloolithus baghensis. This is huge in the world of paleontology and prehistoric research since it would suggest that several species shared the same nesting grounds. The discovery of multiple nests also allows researchers to create biochronological scales that have dated the nests as being 71 and 67 million years old. Since the eggs were also found in multiple layers of strata, more than 25 layers in fact; the discovery also indicates that this particular nesting ground was shared by these species for millions of years.

Findings like these are why paleontologists are in the field. We have just begun to break the surface in terms of paleontological discoveries, which begs the question; what will we find next? And, where may that be?

--Pete D

Photo Credit: Mark A. Stevenson, Deviant Art http://maspix.deviantart.com/art/Sauropod-Herd-303706361

References: 1. http://www.sciencedaily.com/releases/2013/03/130312134912.htm 2. http://www.science20.com/news_articles/coll_de_nargó_4_dinosaur_egg_species_identified-106200 3. http://www.inquisitr.com/576006/hundreds-of-dinosaur-fossil-eggs-found-in-spain/ 4. http://www.bbc.co.uk/nature/life/Sauropoda

For info on a similar discovery that took place in Auca Mahuevo South America in 1993, visit: http://www.facebook.com/photo.php?fbid=364850013576049&set=pb.352857924775258.-2207520000.1363665969&type=3&src=http%3A%2F%2Fsphotos-e.ak.fbcdn.net%2Fhphotos-ak-ash3%2F48144_364850013576049_127195259_n.jpg&size=320%2C239

Gantheaume Point; Broome, Western Australia

The Broome sandstone is up to 286 meters thick in the Broome area and contains massive sandstones, cross-bedded sandstones, laminated siltstones, flaser bedding and conglomerates.

These sandstones represent marine to non-marine environments with variable energy conditions. The weathering and oxidation of metals in these sediments results in the beautiful colouration seen.

These Cretaceous sediments at Gantheaume Point are famous for preserving 130 million year old dinosaur footprints in the rocks below the cliffs. The trackways are by far the most diverse in Australia and includes the only known sauropod trackway in Australia.

Some of the footprint preservation is outstanding and include examples of titanosaurs. This group of dinosaurs includes the largest ever known land animals.

~ JM

Image Credit: http://bit.ly/1Q1TIMF

More Info: Australia’s NorthWest: http://bit.ly/1db75Iy Tracks Below The Tide, Story by Maria Zammit and David Elliot: http://bit.ly/1cv8Rno The Great Cretaceous Walk: http://bit.ly/1eMndkU

The Mesozoic Park: Apatosaurus

Common Name: Apatosaurus, often incorrectly referred to as Brontosaurus Size: about 23 m long, weighed about 16-18 metric tons (16,000-18,000 kg)

Age: Late Jurassic Geographic range: Western U.S. and Canada Liked: Salad, neck massages Disliked: Getting called the wrong name, tiny airplane bathrooms Taxonomy: Animalia > Chordata > Dinosaura > Sauropodomorpha > Diplodocidae > Apatosaurinae > Apatosaurus

Apatosaurus is a sauropod (a group of long-necked, “lizard-hipped”, vegetarian dinos) that was first found in the fossil-rich Morrison Formation that extends throughout the western United States.

Perhaps you haven’t heard of Apatosaurus before, but we bet you HAVE heard of brontosaurus, right? Well…they happen to be the same animal, and Apatosaurus is the politically correct term we are supposed to be using.

Why the name confusion? It all relates back to the Bone Wars (http://on.fb.me/1bIkfvK) and the competition to discover more dinosaur species. Othniel Charles Marsh discovered and named an Apatosaurus skeleton in 1877. A few years later, he unearthed another skeleton that was similar to Apatosaurus but much larger, which hastily led to him to describe it as a new species—brontosaurus. As it turns out, the skeletons were the same species and the first one found was a juvenile. As naming conventions go, the first named species is the term that should be officially used, but for whatever reason, the name “brontosaurus” proliferated pop culture and Apatosaurus didn’t. Some of the first cartoon drawings of dinosaurs were labeled “brontosaurus”, the “brontosaurus” skeleton was one of the first to go up in a museum, the postal service released a “brontosaurus” stamp, and the Flintstones even had a pet brontosaurus and ate “bronto” burgers. So yes, the scientifically correct Apatosaurus got overlooked. There has actually been some recent talk about restoring the brontosaurus as a new species (http://bit.ly/1y0MOPu), but for now we’ll stick to Apatosaurus.

Back to the correctly named dinosaur. There’s a good chance it was one of the largest terrestrial animals… ever. Apatosaurus also had a ridiculously long neck (up to 12 m long) that was buoyed up by air sacs attached to its vertebrae. There’s still a lot of uncertainty about how the animal held its neck—up high to eat leaves from the tallest tress? Or down low, hugging the ground? Most scientists believe its neck was held parallel to the ground, but are unsure how much it could lift or lower it. Apatosaurus also had an impressively long tail, which some research suggests it could crack like a whip and may have used as a defense mechanism. Compared to other sauropods, Apatosaurus had stockier legs.

For many years, paleontologists incorrectly believed the Apatosaurus (and other sauropods) lived in water, which would support their gigantic weight and explain why their nostrils are found suspiciously on top of their heads. However, since the depositional environment Apatosaurus is found in does not indicate a wet setting and they haven’t been found with any other marine animals, we are now more certain they were indeed land-dwellers. Their size is still something to wonder about though—how and why did they get so big? How much did they have to eat to sustain themselves? In any case, the Apatosaurus is quite a marvel (one that somehow did NOT make it into the Jurassic Park movies so far). Just remember to call it by the right name.

-CM

Photo credit: James St. John http://bit.ly/1A1a9BP For more information: http://bit.ly/1EE4X3l This article is a part of our "Mesozoic Park" series that is leading up to the release of Jurassic World. For more information, please see our introductory post at: http://on.fb.me/1ELwHW5 or if you already know about the series but missed a few articles you can find links to the first 10 posts at "Update #1," here: http://on.fb.me/1ED1tOH