palaeobiology

Scientist hails ‘jaw-dropping’ fish fossil discovery

A leading British scientist has said that the discovery of a 419-million-year-old fish fossil in China is a stunning and spectacular development.

Palaeobiologist Matt Friedman told the BBC that the fish provided crucial evidence about the evolutionary development of jawed vertebrates.

As a remote relative of humans, it provides important evolutionary clues.

"It is the deepest branch of our family tree that bears the kinds of jaw bones found in humans,” Dr Friedman said.“

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Jaw Function in Smilodon fatalis: A Reevaluation of the Canine Shear-Bite and a Proposal for a New Forelimb-Powered Class 1 Lever Model

  • by Jeffrey G. Brown

“The jaw function of Smilodon fatalis has long been a source of debate. Although modern-day lions subdue large prey through the use of a suffocating throat bite, the dramatically elongated maxillary canines of S. fatalis suggest an alternative bite mechanism. The current literature favors a “canine shear-bite,” in which the depression of the cranium by the ventral neck flexors assists the mandibular adductors in closing the jaws. Although the model makes intuitive sense and appears to be supported by scientific data, the mechanical feasibility of “neck-powered” biting has not been experimentally demonstrated. In the present study, the computer-assisted manipulation of digitized images of a high-quality replica of an S. fatalis neck and skull shows that a rotation of the cranium by the ventral neck flexors will not result in jaw closure. Instead, the cranium and mandible rotate ventrally together (at the atlantooccipital joint), and the jaws remain in an open configuration. The only manner by which rotation of the cranium can simultaneously result in jaw closure is by an anterior rotation at the temporomandibular joint. Based on this finding, the author proposes a new Class 1 lever mechanism for S. fatalis jaw function. In this model, the mandible is immobilized against the neck of the prey and a dorsally directed force from the extension of the forelimbs rotates the cranium anteriorly at the temporomandibular joint. The maxillary canines pierce the prey’s neck and assist in clamping the ventral neck structures. The model is based on a maximum gape angle of approximately 90° and incorporates a secondary virtual point of rotation located slightly anteroventral to the temporomandibular joint. The Class 1 Lever Model is mechanically feasible, consistent with current data on S. fatalis anatomy and ecology, and may provide a basis for similar studies on other fossil taxa” (read more/open access).

***So maybe not human evolution but this kitten is rad.

(Open access sourcePLoS ONE 9(10): e107456, 2014)

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Nummulites, and why you should be impressed.

These creatures are basically the giants of the microfossil world. They are foraminifera, and are protozoans (single celled organism). What you see in the photos are the tests (solid insides made of low-Mg calcite) and they would have been surrounded by a slimy cytoplasm so they would have been a lot bigger!

Nummulitic limestone is what the pyramids in Egypt are made from, and they are a big deal in terms of correlating rocks in the Eocene of the Mediterranean. 

What is astonishing about them is that they are single-celled organisms, but grow to a massive size! There are still debates about why, but it is believed that they had algae symbionts (diatoms) which helped boost the nummulites’ metabolism so they could grow bigger and live longer! 

Humans Made Conchs Shrink (And One Kid Saw It Coming)

  • by Elizabeth Preston

“The classic, swirling shell of a conch helps protect it from hungry birds and sea creatures, but when a human decides to pluck one from shallow water and boil it for supper, there’s not much the animal can do. Its only defense is to evolve, as a species, to be smaller and less appealing to people. That’s what conchs in the Caribbean have done—today’s humans get 40 percent less food out of a conch than our ancestors did. But that’s not so surprising to a 12-year-old girl who described almost the same thing in a piece of fiction.

To explain the fictional version, I have to insert myself into this story—hello! In my day job I edit a kids’ science magazine called Muse. We recently ran a contest that asked readers to write a brief, made-up story in the style of the magazine’s science news page. (The results were sometimes hilarious. “Too Much Coffee Makes Adults Feel Young” was an office favorite.)

One winner of this contest was a 12-year-old named Madeline. Her submission was about a new species, the “broken-shelled hermit snail” (Mendacious latibulum), discovered on the beaches of North America. It had gone undetected until now, the story went, by evolving a mangled-looking shell that kept human collectors away.

“She is almost certainly right in theory,” says Aaron O’Dea, a marine historical ecologist and paleobiologist at the Smithsonian Tropical Research Institute in Panama. As long as the mollusk were still alive while on the beach and vulnerable to collection, evolving an ugly shell could help it survive. O’Dea knows all about mollusks evolving to avoid humans; he recently discovered that the West Indian fighting conch (Strombus pugilis) has done exactly that.

O’Dea and his coauthors studied conchs living on the Caribbean side of Panama. To see how the animals had changed over time, they gathered shells from three general time periods.

The first was modern shells, which they collected by snorkeling, visiting tourist shops where the shells are sold as souvenirs, and sampling trash piles left by locals who eat the animals. (People sometimes denied gathering conchs for food, even when heaps of shells under their homes told a different story. The authors explain that there’s a regional stigma around eating the conch, nicknamed el raton del mar or “the sea mouse.” In Brazil, though, it’s sold as an aphrodisiac. Earmuffs, Madeline.)

Prehistoric conch shells, from humans’ earlier days living in the region, came from an archaeological site with material dating from around 690 to 1410 AD. In these days humans probably hunted the conch as they do today, wading into the shallows whenever they needed some for dinner. Finally the authors looked at local fossils, about 7,000 years old, to see conchs that had never met a human” (read more).

(Source: Discover Magazine)

I’ve spent the morning sending emails and making phone calls trying to find out if I can get palaeontology work experience to improve my chances of getting on the Bristol masters course once I graduate from Sheffield. I WILL BE A PALAEONTOLOGIST.

Oh and if anyone’s a palaeontologist on here and would either like to be me friend or offer my work experience that would be gr8t thx xxxxxxxxxxxxx

A specimen of Isotelus rex, from Churchill, Manitoba, is the largest complete trilobite ever found. Discovered by Dave Rudkin (Royal Ontario Museum), Robert Elias (University of Manitoba), Graham Young (Manitoba Museum) and Edward Dobrzanske (Manitoba Museum) in 1999, it measures 720 millimetres (28 in) in length, 400 millimetres (16 in) in maximum width (across the cephalon) and 70 millimetres (3 in) in maximum height (at the posterior mid-point of the cephalon).

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Fossil fern showcases ancient chromosomes

Near-perfect 180-million-year-old sample shows the plants haven’t changed much

  • by Meghan Rosen
“After 180 million years buried in volcanic rock in the southern tip of Sweden, a recently discovered fern fossil looks almost as good as new. The matchbox-sized fossil is among the best ever preserved: Thin slices viewed under a microscope reveal rounded cells jam-packed in the stem, like water balloons stuffed in a barrel. And inside the cells, within tiny dots of nuclei, the shadowy squiggles of chromosomes appear.

Such exquisite detail was probably preserved when minerals dissolved in hot salty water rapidly solidified within the entombed, living plant, paleobotanist Benjamin Bomfleur of the Swedish Museum of Natural History in Stockholm and colleagues report in the March 21 Science

Because the fossil’s nuclei closely resemble those of the modern cinnamon fern, Osmundastrum cinnamomeum, the researchers suggest that the plants’ genomes probably haven’t changed much since Early Jurassic dinosaurs prowled the planet.”

(Source: Science News)

I forgot to tell everyone that I finished my degree (Bachelor of Science, Major in Palaeobiology) OMG YAY

I haven’t gotten my results from this semester yet, but provided I have passed everything I am a qualified palaeontologist :D

GIVE ME ALL THE DINOSAURS

… Oh wait, I live in Australia… limited dinosaurs.. :(

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Scaling of Convex Hull Volume to Body Mass in Modern Primates, Non-Primate Mammals and Birds

  • by Charlotte A. Brassey and William I. Sellers

“The volumetric method of ‘convex hulling’ has recently been put forward as a mass prediction technique for fossil vertebrates. Convex hulling involves the calculation of minimum convex hull volumes (volCH) from the complete mounted skeletons of modern museum specimens, which are subsequently regressed against body mass (Mb) to derive predictive equations for extinct species. The convex hulling technique has recently been applied to estimate body mass in giant sauropods and fossil ratites, however the biomechanical signal contained within volCH has remained unclear. Specifically, when volCH scaling departs from isometry in a group of vertebrates, how might this be interpreted? Here we derive predictive equations for primates, non-primate mammals and birds and compare the scaling behaviour of Mb to volCH between groups. We find predictive equations to be characterised by extremely high correlation coefficients (r2 = 0.97–0.99) and low mean percentage prediction error (11–20%). Results suggest non-primate mammals scale body mass to volCH isometrically (b = 0.92, 95%CI = 0.85–1.00, p = 0.08). Birds scale body mass to volCH with negative allometry (b = 0.81, 95%CI = 0.70–0.91, p = 0.011) and apparent density (volCH/Mb) therefore decreases with mass (r2 = 0.36, p<0.05). In contrast, primates scale body mass to volCH with positive allometry (b = 1.07, 95%CI = 1.01–1.12, p = 0.05) and apparent density therefore increases with size (r2 = 0.46, p = 0.025). We interpret such departures from isometry in the context of the ‘missing mass’ of soft tissues that are excluded from the convex hulling process. We conclude that the convex hulling technique can be justifiably applied to the fossil record when a large proportion of the skeleton is preserved. However we emphasise the need for future studies to quantify interspecific variation in the distribution of soft tissues such as muscle, integument and body fat” (read more/open access).

(Open access sourcePLoS ONE 9(3): e91691, 2014)

Australia has this family of giant extinct birds none as Dromornithids. Which are supposed to be nested within Anseriformes (ducks geese and swans).

External image

External image


That massive skull doesn’t exactly look like it belongs to a herbivore though. It’s thought that at least Dromornis and Bullockornis were carnivorous predator/scavengers.
But they don’t exactly have a hooked tip bill that we see in other predatory birds.
But geese have cartilaginous pseudo teeth

External image

So perhaps Dromornithids had these as well, which would have been really really awesome. And scary as hell.


nevermind their hooflike toes, their generally bulky bodies and their wide field of vision with a central blind spot which points to a more herbivorous lifestyle and might just have been a sexual selection characteristic but I want my giant toothy demon ducks of doom shut up

Palaeontology for everyone

The Progressive Palaeontology conference (aside from what may seem a pretty oxymoronic name) is an annual gathering of young research scientists (so masters/PhD/very early post-doc) who all specialize in at least some form of palaeontology.

The ‘progressive’ part of the conference’s title has a little to do with the young age of the delegates, but also due to the techniques being used in palaeontology these days. It’s not unusual now for students researching the fossils of extinct dinosaurs to use engineering principles to, for instance, try to work out how hard T. rex could bite down on its prey (the argument about how important that actually is isn’t for this blog post to consider). 

This year ‘ProgPal’ was held in my University town of Cambridge and we thought it was about time Progressive Palaeontology started progressing into web 2.0. Something that palaeontology conferences aren’t exactly famous for. 

With the consent of the speakers, we recorded all the talks presented as audio files and sent them out into the world here: 

http://progpal2012.tumblr.com/

As to why we just recorded audio files, here’s the final post. 

Progressive Palaeontology is a student conference organized by students. This year we felt that allowing anyone to virtually attend the conference was in keeping with the current rumblings within academia and academic publishing. All the speakers on this tumblr agreed to have their talks recorded and shared online. They also provided the information and links beneath their talks.

As ProgPal is a conference for young researchers, some of the information and results discussed may not have yet been published. For this reason, we decided against recording visuals, just in case a super sexy scatterplot on a slide accidentally internally-scooped one of the speaker’s labs.

However we all agreed that the gains brought about by sharing the conference with the whole world online meant that this was (of course) the right thing to do. We look forward to seeing more international conferences offering access to talks online when, for instance, delegates are often unable to travel the large distances to foreign universities.

Now all that’s left is for us to wish the organizers of next year’s ProgPal all the best and to hope they keep using the #progpal hashtag.

We’re looking forward to it.

So, if you’ve got a few minutes and you fancy finding out about Icthyosaurs, crurotarsans or, yes, dinosaurs. Take a peek. 

It’s free knowledge!