Tuesday, February 25, 2014

UNSUNG WEIRDOS I: CROCS THAT ATE PLANTS






There are few things as frightening as the idea of being attacked by a large crocodile.  It is truly the stuff that nightmares are made of. 

Sandy Rossi can testify to that.  When 27 years old she lost an arm to a Nile croc in the Epulu River in Zaire --- a river that isn’t normal habitat for Nile crocs.  She just happened to have the misfortune of running into a wanderer.  As she rinsed her hair at the river’s edge the croc struck, grabbing her by her arm, dragging her underwater and beginning death rolls.  "You could just feel the power," Rossi said. "He'd yank me back and forth to see if I was dead yet. Then he'd roll me some more."  I vividly remember watching a TV interview with her where she chillingly recounted how she was relieved when her arm came off because she realized she finally had a chance to get away from the jaws of death. So she lost part of an arm but escaped with her life.





Today crocodilians are top predators in freshwater and estuarine environments. Salt Water crocs even traverse marine waters to get to off shore islands. Throughout their long 200,000,000 + year evolutionary history one group or another of crocodilians has occupied the niche of top freshwater predator. The immense late Cretaceous Deinosuchus could certainly kill dinosaurs, including T. rex. But today’s crocodilians give the wrong impression of the wonderful evolutionary history of this group. This is a case where the present is not a good guidebook to the past.

The crocodilian fossil record reveals that in the past these animals had a much more diverse, and sometimes surprising, anatomy and ecology, making livings in ways quite different from extant species. Some were slenderly built, long limb terrestrial runners, some were filter feeders, some were capable of walking just on their hind legs.  And some, maybe the most amazing of all, gave up the carnivorous lifestyle completely and became plant eaters!

Simosuchus clarki is the weirdest of all known crocodilians living or extinct. One can be forgiven for not even recognizing it as a crocodilian in the first place.  Known only from the Cretaceous age of Madagascar the first specimen was described in 2000. But since then on-going field work on the island has produced multiple additional specimens, all very well preserved --- which is a good thing given how truly odd this beast is.


A restoration of the pug-nosed Simosuchus, a most improbable crocodilian.



Simosuchus was not a giant; just a mere 2 ½ feet in length and weighing around 20 lbs.  The body was completely enveloped in a dense, closely packed set of boney armor plates.  This armor severely restricted the side to side motion of the body and along with the short stubby tail, is strong evidence that Simosuchus was a land dweller and not a swimmer.

The skeleton of Simosuchus (above) is strikingly different than that of an alligator (below).






However, it is the skull that is most unusual and so highly specialized that it appears nothing like the living crocodilians we’re accustomed to (and I won’t even bother with all the detailed technical skeletal specializations in the skull).  The most important thing to remember is that these fossil skulls are complete and uncrushed.  The “missing” long snout is not broken off, rather Simosuchus evolved a very short face with a squared off snout.  This pug face inspired the generic name, which means “pug-crocodilian”.

Skulls of an alligator (left) and Simosuchus (right) viewed from above.



Skulls of an alligator (left) and Simosuchus (right) in side view.


Even more bizarre are the teeth.  The vast majority of crocs have pointed, conical teeth, just perfect for puncturing and holding onto flesh (and human arms).  No so Simosuchus.  This weirdo has teeth that are flattened side to side, with a blunt crown bearing a few denticles.  Teeth of similar shape are found in several living herbivorous lizards as well as a range of extinct herbivorous reptiles, including plant-eating dinosaurs.  Recent analysis of the jaw mechanics of Simosuchus shows that this creature was not able to generate enough force to cut through protein (i.e. muscle and skin) but just could generate just enough to cut through cellulose (plant tissue). 

Teeth of an alligator are just fine for puncturing delicate skin and muscle.



The teeth of Simosuchus, too weak to cut muscle, were just fine for slicing up plant material.

Simosuchus is known from remarkably complete skeletons and skulls and has been analyzed in great detail in a number of scientific publications. All authors agree that Simosuchus was a crocodilian that had left meat eating habits behind and evolved into a plant eater.  But it might not be the only one to do so.

Simosuchus is closely allied to the Notosuchia, an extinct group of small crocodilians found in Cretaceous rocks South America, Africa, Asia, and Europe. They all have shortened faces, although not as severely a truncated snout as in Simosuchus, and are terrestrial in habit. Notosuchians also show remarkable tooth specializations, some evolving a multi-cusped tooth crown structure like that seen in mammals, and it is likely that a number of notosuchians were plant-eaters. Since they are not dinosaurs, notosuchians don’t get much press, making them unsung weirdos, with Simosuchus serving here as tip of the herbivorous crocodilian iceberg.





SOURCES


2010. Simosuchus clarki (Crocodyliformes: Notosuchia) from the Late Cretaceous of Madagascar.  Journal of Vertebrate Paleontology Memoir 10: 236 pp. [Part I: Overview of the discovery, distribution, and geological context of Simosuchus clarki (Crocodyliformes: Notosuchia) from the Late Cretaceous of Madagascar.  Part II: Craniofacial morphology of Simosuchus clarki (Crocodyliformes: Notosuchia) from the Late Cretaceous of Madagascar.  Part III: Postcranial axial skeleton of Simosuchus clarki (Crocodyliformes: Notosuchia) from the Late Cretaceous of Madagascar.  Part IV: Appendicular skeleton of Simosuchus clarki (Crocodyliformes: Notosuchia) from the Late Cretaceous of Madagascar.  Part V: Osteoderms of Simosuchus clarki (Crocodyliformes: Notosuchia) from the Late Cretaceous of Madagascar.  Part VI: Phylogenetic history of Simosuchus clarki (Crocodyliformes: Notosuchia) from the Late Cretaceous of Madagascar.]

Gignac, P. and Kley, N. 2013. Inferences on the feeding biomechanics of the bizarre pug-nosed crocodyliform Simosuchus clarki. Journal of Vertebrate Paleontology, Program and Abstracts, 2013: p. 84.


Salter, J.  Crocodile Attack Can't Destroy Her Love of Life: Africa: Spirited Missouri woman lost her arm to deadly reptile a year ago. Undaunted, she's preparing to revisit the remote forest in Zaire where she nearly died. L.A. Times on-line http://articles.latimes.com/1994-05-22/news/mn-60701_1_crocodile


ILLUSTRATIONS

Nile crocodile feeding triptych:  

Crocodile with human hand

Modern Alligator skull: Jollie 1962 (modified)

Simosuchus skeleton: Journal of Vertebrate Paleontology Memoir 10 Part I
Simosuchus skull and teeth (modified): Journal of Vertebrate Paleontology Memoir 10 Part II
Simosuchus restoration:  Journal of Vertebrate Paleontology Memoir 10 Part I

Modern Alligator mississippiensis skull: Jollie, M. 1962.  Chordate Morphology. Reinhold Press: 478 pp. (modified)

 

Monday, January 13, 2014

BEJEWELLED BONES





The adorned remains of Saint Felix, once of the parish of Tafers, Switzerland now on exhibit at the Museum of Art and History in Fribourg.


A remarkable amount of my life has revolved around bones, both recent and fossil.  I have cleaned them, excavated them, scrambled across rocky landscapes under the blazing desert sun looking for them, mused and mulled over them, measured them, photographed them, x-rayed them, CT scanned them, preserved them, conserved them, cursed them, praised them, read about them, written about them, molded them, cast them, put them on exhibit, accumulated well in excess of 10,000 books, scientific papers, and pdfs about them, and discussed them with students and colleagues across the globe.  Many people I know have done the same  - it’s par for the course for vertebrate paleontologists. Given that experience, one might become jaded about bones, but that hasn’t happened to me yet. I still find bones of great interest and am challenged by the story they tell us about the evolution and biology of life on Earth. 





However, I recently read two books that, in spite of my many decades of working with vertebrate fossils, revealed to me a new and wonderful story about bones, this time about the human skeleton.  The Empire of Death: A Cultural History of Ossuaries and Charnel Houses and Heavenly Bodies: Cult Treasures and Spectacular Saints from the Catacombs are by Paul Koudounaris, who holds a PhD in Art History from UCLA and so has a scholar’s interest and knowledge of his subject matter. He visited over 70 sites on four continents while researching these books. In addition to his keen intellect, Dr. Koudounaris possesses the all too rare ability to write about technical subjects in an engaging, easy to understand style that keeps the reader interested without sacrificing accuracy or the deeper meaning of what he writes about.  On top of that, the books are lavishly illustrated with hundreds of spectacular photographs that are even more riveting than the text. So when you finish these books you not only come away with a skull crammed full of new details but you will want to immediately turn back to the first page and start again.  These are not books you only read once. You will reread them and share them with friends and family, although how they will react is another matter.


 

Although this is known as The Chapel of Skulls in Czermna, Poland, the ceiling is made of lashed together human thigh bones.
 
I’ll just give the briefest outlines of what the books are about and show a few images.  If you find this of any interest whatsoever, track down these volumes – you will not be disappointed. Take the world tour via the printed page and remember that a number of these sites are open to the public. Someday you might be in the neighborhood and can pay a visit.



The Chapel of Bones (and indeed it is), Parish Church of Nossa Senhora da Expectacao, Campo Maior, Portugal.

The Empire of Death explores our changing familarity with the skeletal remains of dead. In the not too distant past, interacting with the bones of the dead was an important part of Christian spiritual life.  Bones were amassed, sometimes in staggering numbers. 

The Paris Catacombs contain the remains of as many as 10,000,000 Parisians, with vast walls piled up by type of bone, sometimes with skulls arranged to spell out Latin phrases. In other cases, tens of thousands of bones literally line the walls and hang from the ceilings of chapels.  Full skeletons were dressed up in robes, armor, vestments, and other clothing.

 

Tomb of Enrique Torres Belon, Church of Sanitago Apostol, Lima, Peru.


These sites were seen as sacred and worshippers went to them to solicit aid from the dead.  Unlike today, people were not repulsed by the dead but instead saw them as a source of help and hope.  As can be seen in the photographs in The Empire of Death, a number of these churches still have magnificent remains in-place.

 

The remarkable 8 foot wide chandelier is made of human skulls, limb bones, and pelves, All Saint’s Chapel, Sedlec, Czech Republic.
Heavenly Bodies traces the strange history of skeletons from the Roman catacombs.  During the battles of the Protestant Reformation in 16th century northern Europe, many Catholic churches were sacked and their religious reliquaries and holy objects wantonly destroyed as non-Christian. As part of its counter reformation, the Catholic church sought to re-establish itself in those areas and replace the holy objects that had been lost.  But where to get so many saintly objects in such a short time?  From the Roman catacombs of course, where first century corpses were in abundance (although many of them were of pagans).  With little or no information about the bodies, church officials, including the Pope simply declared them saints, sometimes en mass, gave them names, sold them to distant churches, and shipped them off. 



The dressed and bejeweled skeleton of Saint Felix, Gars am Inn, Germany.

They were received with great fanfare and proudly and prominently exhibited in churches.  To better honor these holy relics, nuns, at great expense, sewed clothing for the corpses/skeletons and often festooned them with colored glass, gold, and precious jewels.


 

Saint Gratian in Waldassen, Germany dressed in sumptuous Roman military attire.

These “catacomb saints” remained powerful religious emblems and objects of adoration in the churches until the late 18th and early 19th century, when they began to be seen as too ghoulish or idolatrous to remain there.  Many were destroyed or removed and put in storage. Some are still in public areas.

Regardless of your visceral reaction to the outlandishly decorated skeletons, one cannot deny the beauty of the sewing and wirework, the attention to detail, and the ornate jewelry worked into the clothing and sometimes the bone itself.


Fine eye, nose, and dental wirework on Saint Benedictus, Hergiswil, Switzerland.

Paul Koudounaris' personal website www.empiredelamort.com is, as he states “an online resource for charnel houses and burial catacombs, and a supplement to the book The Empire of Death”.  It contains spectacular photos and information on even more sites than are in his books.  It is well worth a visit.


PHOTO SOURCES

Koudounaris 2011: The Chapel of Skulls, The Chapel of Bones, Tomb of Enrique Torres Belon, All Saint’s Chapel

Koudounaris 2013: Saint Felix (Tafers), Saint Felix, Gars am Inn, Saint Gratia, Saint Benedictus


SOURCES

Koudounaris, P. 2011.  The Empire of Death: A Cultural History of Ossuaries and Charnel Houses. Thames and Hudson Press. 224 pages 

Koudounaris, P. 2011. Heavenly Bodies: Cult Treasures and Spectacular Saints from the Catacombs.  Thames and Hudson Press. 192   pages