Friday, March 18, 2016

A juvenile Tyrannosaurus braincase?

 

An exciting development (maybe) this week for #FossilFriday. On the left is a braincase fragment from one of our new 2015 sites. On the right is the braincase of Timurlengia, a small tyrannosaur from Uzbekistan described this week by Brusatte et al.. Now, this photo is of the inside of the braincase, and I was struck by the similarity to our specimen. Could we have a (juvenile) tyrannosaur skull coming out of our site? When we found it we realized it was a braincase of course, and it is a bit too gracile to be from an ornithischian (we think), but there are not too many specimens to compare it to.

It's only a fragment I know, but that's how you find these important sites: ID the frags and dig deeper! (besides, this site already has a juvie pachy and thescelosaur...)

Opinions welcomed!

Hell Creek Formation. American Prairie Reserve. Montana.

Friday, October 30, 2015

Iguanodon Footprints cast in red mudstone for Fossil Friday

It's been a while since I posted fossil photos for "Fossil Friday", so here are the missing photos that I posted to Facebook over the past few weeks.

Iguanodon Footprints

Although dinosaur footcasts preserved in Wessex Formation sandstones are perhaps more obvious, there are many preserved out in the vividly coloured mudstones too. Infilled footprints can often be found at the boundary (contact) between beds of different colours. This red-infilled footcast was probably made by an Iguanodon.

Wessex Formation, Barremian, Lower Cretaceous, ~130 Ma, Grange Chine, Brighstone foreshore, Isle of Wight, UK.


The three toes of the hindfoot are especially well defined in this footcast.
Here is another in the same horizon, a little more weathered.

This is the exposure itself at Grange Chine (Brighstone foreshore). You can see two red footprints in the foreground.

 

 

Ammonites in the lower chalk 

Collecting ammonites from the glauconitic marl with my dad and brother (pictured). Usually you find small Schloenbachia and Mantelliceras, but occasionally the big species turn up. Old Park Hotel, Isle of Wight, UK; Lower Chalk, Cenomanian, ~95 Ma, Upper Cretaceous.

How many ammonites can you see in this picture?


A mammoth day out

Back in the day, I used to run fossil-hunting field trips for armies of ten year olds. This is probably the best thing ever found on my trips: a mammoth tooth. We were actually looking for dinosaur bone in the Wealden, but Letitia brought this up to me and asked what it was, so I then had to explain about the Pleistocene gravels that form the upper 2m or so of the cliffs. This was shortly after we met a man on the beach who had found a lost baby stoat and had it crawling around all over his jacket. The kids were already pretty excited about that, so the mammoth tooth sent them wild!

 
This was quite a few years ago now. Still better than anything I have found from the Pleistocene.


Some associated pterosaur bones

Some pterosaur bones for #fossilfriday. My dad collected these a few years ago from the Vectis Formation, UK. Pterosaur material is supposedly rare, but turns up fairly regularly if you know what to look for. Collecting pterosaur bones in the UK helped me to identify a few pieces that I have found or helped describe from the Late Cretaceous of the USA. One day I will get round to describing the pterosaur bits we have found in the UK too.

Vectis Fm, lower Aptian, Lower Cretaceous, Isle of Wight, UK.

Pterosaur limb bones in coquina (storm bed) dominated by the bivalve Filosina.



Fossil lobster (okay, it's more shrimp-sized...)

A small Meyeria magna lobster, preserved in 3D. These are very attractive little fossils, and quite abundant if the right layer is exposed and you know what you are looking for.

Lower Lobster Bed, Lower Greensand (Aptian), Atherfield, Isle of Wight, UK.


Everyone likes to find fossil crustaceans, especialy when they have fine detail such as the tiny spines on this Meyeria.
 

Sunday, October 4, 2015

When stegosaurs had smarts

This week, I'm posting scans of a recently acquired postcard.

The postcard dates from around the 1960's, but it features an 1895 poem which regales the hypothesis that an enlarged space in the pelvises of many dinosaurs meant that they might have possessed a second brain. Paleontologists are still interested in the possible function of the swollen spinal canal, but it is no longer considered to have housed a hindbrain.

Anyway, I thought the poem was quite clever, so here it is:

Front of postcard

Reverse of postcard

Another poem, this time from 1885, similarly reflects the Victorian fascination with paleontology. I sometimes wonder what was different about this time in the recent past, when scientific discoveries were so ingrained in the public consciousness that leading newspapers and magazines treated them not only as interesting facts, but as cultural objects of inspiration and humour. The modern media seem concerned only with the frivolous lives of shrill celebrity dimwits, or the opinions of boorish career politicians.

Anyway, I digress. This second (somewhat overlong) poem concerns the enormous eyes of the extinct marine reptile, Ichthyosaurus. I liked it. You should too.

From Punch magazine (1885); http://catalog.hathitrust.org/Record/000682156

Inspired by these kinds of things, since about 2011 once per field season my paleontology field crew have held a poetry evening, where we attempt to recount our experiences in pithy prose. Maybe if I can find some of the poems I will repost them here... or at least some of those that are repeatable in polite society...

Okay, back to work...

--- edit 6th October ---
I just noticed the implicitly racist "Aryan brain" line in the Ichthyosaurus poem. Apologies if anyone was offended; obviously this is a representation of the kind of discriminatory language and attitudes that were widespread in Victorian society.

Friday, September 18, 2015

Fossil Hedgehogs


A slightly different #fossilfriday this week ( I missed last week as I was busy hiking and looking for fossils on the American Prairie Reserve). Back in 2000 I found a very productive seam of microvertebrates in the Oligocene Hamstead beds of Boldnor on the Isle of Wight. We retrieved something like 300 mammal teeth from only about 1-2 kilos of sediment. Jerry Hooker (Natural History Museum, London) came over to Bristol University to see the fossils and told me that among our cache were the best preserved oldest hedgehog teeth in the world. I gather that there are older hedgehog remains, but these teeth are the best preserved. Anyway, everyone likes hedgehogs, so I was very pleased.

Fossil Hedgehog teeth. Adapted from Hooker (2010).


The specimens were donated to the NHM to be studied by Jerry. The above image is a figure from his 2010 paper and shows Scanning Electron Microscope photos of hedgehog teeth from Hamstead. I do not know if the teeth shown here are the ones I found, but I suspect they are.

The hedgehog teeth are part of the fossil fauna from immediately after the Grande Coupure extinction event that occurred in the northern hemisphere in the earliest Oligocene, about 34 million years ago.

This image is a bit plain though, so here's a photo to remind you of how cute hedgehogs are:

(image from pinlovely.com)

Reference

Hooker, J. J. "The ‘Grande Coupure’ in the Hampshire Basin, UK: taxonomy and stratigraphy of the mammals on either side of this major Palaeogene faunal turnover." Micropalaeontology, Sedimentary Environments and Stratigraphy: A Tribute to Dennis Curry (1912–2001) (2010): 147-215.

Friday, September 4, 2015

Baby Iguanodons!

Here are a couple of pictures of baby Iguanodon fossils that I have posted to Facebook for #FossilFriday.

This week: baby aff. Iguanodon tooth 

 A very small (~9mm) crown of a juvenile aff. Iguanodon from Chilton Chine, Wessex Formation, (Barremian, Lower Cretaceous, ~130 Ma), Isle of Wight, UK.


Aff. Iguanodon juvenile dentary tooth.
Scalebar in mm. Photo: Steve Sweetman.

Iguanodontid material is common in the UK Wealden, but juvenile material is always nice to find. This looks to be a dentary tooth, based on the broad diamond shape. For comparison, here's a photo of a medium-sized adult dentary tooth from Iguanodon bernissartensis:
 
Iguanodon bernissartensis tooth.
Photo from dinowight.org.uk

A few weeks ago: The best Iguanodon fossil

A few weeks ago (on my Facebook page), I posted this photo of another juvenile Iguanodon bone. It's a tiny thumb spike! The spike is a little bit worn as it has been rolling around the beach for a while, but you can see the "nail groove" running down the side.

When I found this back in the 1990's, I was not particularly experienced in identifying bones, so for a while I thought it was a crocodile tooth, but it is clearly bone.

Juvenile aff. Iguanodon thumb spike.



Friday, August 28, 2015

A Baryonyx tooth for #FossilFriday, plus blog bonus!

The unique crocodile-like tooth of Baryonyx





Tooth of the english fish-eating spinosaur Baryonyx walkeri. Possibly my favourite of the ~20 or so Baryonyx teeth I have collected (mainly due to the rich red and yellow colours), this is also the stratigraphically lowest, being from half way through Sudmoor bay. Wessex Fm, Barremian, Early Cretaceous, Isle of Wight, UK.

If you like Baryonyx teeth you can find another 20+ illustrated on my SVP poster from 2007. 15mb PDF available here.



Blog bonus!


I recently came across this old press photo (1983) for sale on the internet. The photo shows the original discoverer of Baryonyx, Mr. William (Bill) Walker, along with Sandra Chapman at the Natural History Museum, London. If you're as big of a fan of Baryonyx as I am, then you are probably familiar with the iconic photo of Bill Walker holding up the claw of the dinosaur that bears his name, but I had not seen this photo before (presumably taken at the same sitting). Enjoy!

Sandra Chapman (left) and Bill Walker (right) hold the enlarged hand claw of Baryonyx walkeri.
John Sibbick illustration in the background.
Vintage press photograph for sale at internet shopping website.

Presumably the flip side of the photo.

Friday, August 21, 2015

Iguanodon for Fossil Friday

#Fossil Friday

Over the years I have collected lots of fossils from all over the globe. I have started posting photos of these to my facebook page for #FossilFriday. I'm going to post them here on the blog too.

So far I've been focusing on fossils I have found on the Isle of Wight, UK. This is the best place in Europe to find dinosaur fossils.

So here's this week's image:

Iguanodon. The best dinosaur, or your money back.
This is the nicest Iguanodon tooth that I have found, which is not saying much really. The tooth is from the maxilla (upper jaw) and is nicely preserved as it is unworn, i.e. it had not yet been used by the dinosaur to chew with.

I suppose technically I should say that this is <probably> from Mantellisaurus, which is the new name for Iguanodon atherfieldensis. I'm not a big fan of taxonomists constantly renaming taxa. Collected from the Wessex Fm (Barremian; Lower Cretaceous, ~130 Ma), Brighstone, Isle of Wight, UK.


If you would like to see previous #FossilFriday posts on my Facebook page, head to the album here.

Thursday, July 23, 2015

Screenwashing, for victory!

So if you followed the link from my previous post over to the Great Plains Dinosaur Museum Facebook page, you would have seen a photo of a cute little pachycephalosaur squamosal spike that we found in the first week. Pachycephalosaurs are the famous dome-headed dinosaurs that are often shown headbutting each other (although the evidence supporting this behavior is controversial).

This pachycephalosaur spike came from "trucker's macrosite" which preserves a jumble of bones from various different species. Most of the time, bones in macrosites are water worn, or broken, but a small percentage are better preserved, so macrosites can be good places to look for skull bones, and other diagnostic elements.

One of the other interesting pieces collected from "truckers macrosite" is this fragment:

A braincase fragment from a theropod?
The specimen is constructed from quite thin-walled bone, and has numerous holes ("foramina") passing through it. I was wondering if this might be part of the braincase of a theropod dinosaur. The foramina would therefore represent the holes though which the cranial nerves passed. If anyone has a better idea for the identification of this bone, then I would be very appreciative (I am hoping it is not just parts of a large theropod vertebra).

Trucker's macrosite yielded additional pieces of theropod skull, but each of the interesting specimens from this site is incomplete, with broken ends where (presumably) pieces had broken off during recent weathering. So, in an attempt to find the missing parts of these tantalizing fragments, we returned to the site yesterday to do some intense surface collecting and screenwashing.

Peter Thomas (foreground) and Danny Anduza (shirtless) search for more treasures. Photo by Holley Flora.

Peter, Danny and Holley spent all day collecting every piece of bone from the surface and dry / wet screenwashing shovels of mud to find pieces that had been buried. Today we were trapped in camp by rain, so I started going through the surface collected material to see if we had any of our missing pieces.

Success!

Inside the third bag I looked in (collected by Holley) I found this little gem:

Pachycephalosaur squamosal spike, number 2!
The spiked tip is missing, so we will be back screenwashing again to try and find it!
Crewmember Holley Flora (one of my seasoned field crew from 2013 & 2014) had picked up another squamosal spike from a pachycephalosaur! This is almost certainly from the same specimen as our previous spike, so it is possible that there might be more at the site.

Pachycephalosaurus wyomingensis by Dr. Jordan Mallon.
The spikes we have found are from the back corners of the skull (squamosals) .
(Image from wikipedia)

You might be familiar with the recent research by my supervisor Jack Horner and Mark Goodwin from UCMP Berkeley. In 2009 they hypothesized that the dome and squamosal spikes of Pachycephalosaurus changed through growth. Young animals had no dome, but exhibited long spikes on the squamosals. The characteristic dome-head of Pachycephalosaurus developed through ontogeny, and was only fully-sized in adults. Curiously, adult Pachycephalosaurus had short rounded knobs on the squamosal, instead of the long spikes of youth.

The spikes that we found are quite small and fairly pointed (based on the angle of the sides, as the tips are missing), so we would interpret them as coming from a young Pachycephalosaurus.

As a bonus, in the next few bags of bone fragments, I found quite a few new pieces to go with the possible braincase. Overall, not a bad return for a rain day!

Reference



Friday, July 17, 2015

New juvenile Triceratops and pieces of theropods

From a slow start... finally warming up

During our first week in the field we discovered many important microsites, but I was disappointed with the lack of sites yielding decent large material. However, in the past week we have started to find a few acceptable skeletal sites (and of course, even more microsites!), which is what I'll be reporting on here.

I'm also going to try and blog a bit more often, but with shorter posts each time.

Understanding growth in Triceratops-  a new juvenile Triceratops

One of the ongoing research projects for my coauthor John Scannella, and supervisor Jack Horner is the growth of the horned dinosaur Triceratops. We are especially interested in changes in the shape of the frill from juveniles through to adults, so any new discoveries of juvenile material is very welcome. In the first week we found a fragment from a juvenile Triceratops frill (which we collected) but a few days ago crew member Jack Wilson found a better partial frill which he called "Jack's Blue Juvie Trike":

"Jack's Blue Juvie Trike": Jack's new juvenile Triceratops includes this piece of the parietal (middle of the frill) and three "epiparietal" spikes.

Although it is quite fragmentary, "Jack's Blue Juvie" specimen preserves just the right pieces to tell us some new information about the ontogeny of the frill border. Research by Jack Horner and Mark Goodwin (Horner and Goodwin, 2006; 2008) has shown that in juvenile Triceratops (as seen here), the epiparietals are shaped like equilateral triangles and are unfused or "loose" on the edge of the frill. Through growth, the epiparietals become much less pointed, flattening into a spindle shape and completely fusing to the frill border in adulthood.

Complete Juvie Trike: This is "DF Juvie Trike III" that I found in 2008.
(skeleton on display at Museum of the Rockies, Bozeman; skull on exhibit at the Burpee Museum, IL, and the Smithsonian in Washington DC!).

"Count Trikeula" -an adult Triceratops

We have found a few adult Triceratops sites, but most of these have been quite poor. However, we have finally knocked into a decent Triceratops site which crew member Danny named "Count Trikeula":

Count Trikeula: After a few false starts, our first decent Triceratops site. Here (if you know what you are looking at) you can see part of the epijugal (cheek spike), and the edge of the squamosal (part of the frill).
Despite there being many fine Triceratops skulls in museums, most of these frustratingly lack any contextual data, so are not very useful for understanding Triceratops evolution. Sadly, this is especially true of the holotype(s) of Triceratops held at many venerable institutions on the east coast. 

However, recent collecting by the Museum of the Rockies (Montana State University) and UCMP Berkeley recovered ~100 new Triceratops skulls, and we took care to record contextual data, especially the stratigraphic position of the specimens (whether they occur in the lower or upper parts of the Hell Creek Formation). This effort has revealed that Triceratops evolves from the species T. horridus in the lower Hell Creek Formation to T. prorsus in the upper Hell Creek Formation (Scannella et al., 2014). If our 2014 paper is correct then "Count Trikeula" *should* be a Triceratops horridus. In this way, every new Triceratops specimen we find can be used to test the hypothesis proposed in the Scannella et al., (2014) paper.


Theropod bones

We've had quite a bit of luck finding bones from theropod dinosaurs, including some exceptional odds and ends that will be used for some new research. I'll be posting a bit more on these in the future, but in the meantime here are a few photos:

Theropod femur: This is a femur from a medium-sized theropod; either an immature T. rex, or maybe a very large ornithomimid (ostrich mimic). We dug around the bone but did not find any more bones at this site, so it looks like it is isolated, and not part of a skeleton. In the lower Hell Creek Formation, it is commonplace to find isolated bones like this, and they tend to be covered in a thin layer of white concretion, with the bone itself is fairly brittle. Theropod femora are not common finds however, so we will be jacketing and collecting this specimen.

Raptor phalanx: This is a toe bone from the foot of a small "raptor" dinosaur. I have published a few research papers on how small carnivorous dinosaurs might have used their feet in capturing and killing prey (Fowler et al., 2009; 2011), and even isolated finds like this can be informative.

BONUS 1! : Mystery bone

My crew and I are pretty good at identifying bones in the field. However, occasionally we come across interesting little fragments that have a distinctive shape, but which we cannot immediately identify. Many of these "mystery bones" have turned out to be important finds in the past, so we make a habit of picking them up. So in that vein: does anyone have an idea what this mystery bone might be?

Mystery bone: an isolated fragment from a channel lag deposit. The foramina and texture looks like skull fragment, but the bone is robust enough to suggest it is not from a theropod dinosaur. I was thinking it might be part of the lower jaw, maybe the distal end of a dentary where a predentary might attach. It has enough morphology to be identifiable. Suggestions welcome in the comments!


BONUS 2!: Great Plains Dinosaur Museum, Malta

Some of the fossils that we have found are temporarily on exhibit at Great Plains Dinosaur Museum, Malta. I have intentionally not mentioned a few of the things that are on display there, and you will need to visit the museum's Facebook page to see them (or even better, visit in person!). There are going to be some nice fossils going on display there in the next week or so.

Okay, we're heading off to do some more prospecting!

Denver.

References

 
Fowler, D. W., Freedman, E. A., Scannella, J. B., & Kambic, R. E. (2011). The predatory ecology of Deinonychus and the origin of flapping in birds. PLoS One, 6(12), e28964.

 

Sunday, July 5, 2015

First report: bad weather and microfossils

Murderwind!

So... last night we were hit by 60-80 mph winds and large quarter/golfball sized hail.

50-cent coin sized hail!
(Photo: J. Wilson)

My cheap tent was destroyed by the hail (I have a replacement). Hail also blasted the skylights off the trailer and put some holes in other plastic fixings around camp. The truck is okay. (Photo: J. Wilson)

Today we are clearing up debris, drying out sleeping bags, and cannibalising my tent to fix holes in others.

Prospecting for dinosaurs

The past couple of days we have been out prospecting and found some interesting things. We haven't come across a particularly good dinosaur site yet; We discovered four sites with scrappy Triceratops remains, and crewmember Danny found a Triceratops site that had nice preservation quality:

"Horns of Plenty": This is part of the frill of a Triceratops. This could have been a good site, but we could not locate the bone layer as it was very overgrown with plants. No matter, we will find another.

If we had been prospecting in the upper Hell Creek, then I would expect to run into a Triceratops site every 200 metres or so. However, the lower Hell Creek is much less rich for fossils, so we have to cover much more ground. We will keep looking, and I am sure we will turn up something good eventually.

Microsites

Despite not finding much large material, the past few days we have recorded four good microsites. Microsites yield lots of tiny fossils like teeth and small vertebrae, and occasional larger fossils like finger and toe bones (phalanges) and claws. Microsites are used by paleontologists like Dr. Greg Wilson and his students to study how the complete fauna of the Hell Creek Formation changes through time. Our new localities are all very low in the Hell Creek Formation, and so should provide valuable datapoints.

This is a metatarsal III (middle toe) of either a medium-sized Tyannosaurus rex, or a large ornithomimid dinosaur. This specimen was recovered from Danny's site "Danny's rex micro".

This is a tooth from a dromaeosaurid: a small "raptor" dinosaur. Jack Wilson found this at his site "Jack' Neck Microsite". This site is potentially SUPER-EXCITING as it yielded the posterior end of a cervical (neck) vertebra which *might* be from a pterosaur (which are incredibly rare in the Hell Creek). Black bar width 1cm.

Fish remains from"Warwick's diddy Microsite": a skull plate (left); two vertebrae (top); a ray tooth (right), and a toothed palate (bottom middle). Scale in cm.

A champsosaur vertebra (left) and turtle fragment (right) from "Warwick's diddy microsite".

Two phalanges (toe bones) from "Warwick's diddy microsite". Scale 1cm.

Tyrannosaurus teeth. Often commercial collectors will sell small teeth like this as "Nanotyrannus", but it has not been demonstrated that Nanotyrannus is actually a unique species. Research by tyrannosaur expert Thomas Carr (and others) shows that purported Nanotyrannus specimens actually represent immature Tyrannosaurus.

Teeth from the small raptor-like dinosaur Richardoestesia. No-one knows what Richardoestesia looked like as so far scientists have only found its teeth. These are very unusual-looking for theropod teeth, suggesting that this species might have had an unusual feeding method or ecology.

Another dromaeosaurid "raptor" tooth.

I'm saving the second-best fossil for last (assuming that Jack's vertebra is pterosaur). Here is a jaw of a marsupial found two days ago:

Marsupial lower jaw. I am hoping some mammal expert can help identify this specimen in the comments. It looks to me like Glasbius sp. maybe, or something related?

Ok, back to cleaning up camp!