Paleontology

I’ve already mentioned that my time in Canada involved a short trip to Dinosaur Provincial Park with Darren Tanke, but we were also out with Mark Graham, a preparator at the Natural History Museum in London. Mark has kindly written up a guest post on the trip and the hunt for the lost Spinops quarry. Mark preparing Spinops The recent  Fossil Preparation and Collections Symposium (FPCS) hosted by the Royal Tyrrell Museum in Drumheller, provided a great opportunity for me to give a talk about the recent conservation and mounting of a large skull of the ichthyosaur Temnodontosaurus platyodon and also to team up with Darren Tanke for some fieldwork in Dinosaur Provincial Park to try and find the location of a lost quarry. The quarry we sought had contained, in 1916, a bonebed of material which the legendary Sternbergs had collected for the then Geological Museum in London (now the NHM). Among the specimens collected was the partial skull and parietal elements of a horned dinosaur – a centrosaurine ceratopsian – which I had the privilege of preparing in 2008. It was a new species named Spinops sternbergorum and it was through this work that I got to know Darren (we were co-authors on the descriptive paper). He suggested that I take along a sample of the Spinops matrix so that we could use it to try and match the distinctive ironstone to exposures in an area “3 miles upriver from Steveville”, which the Sternbergs had recorded as the location of the find in their field notes. Locating abandoned quarries in the badlands from clues left in old photographs, fieldnotes, quarry markers and litter is something of a speciality of Darren’s and so I tagged on three days holiday at the end of the symposium to do some sleuthing with him. Spinops quarry material, replete with ironstone Dave Hone was also at the Tyrrell, undertaking research with Darren into bite marks on fossil bones and he also attended the symposium and gave a very insightful presentation titled ‘Scientific Communication of Fossil Preparation in the Digital Realm’ [Dave adds: this should go online at some point]. This discussed how his blog had been used to communicate Darren’s prepwork on the tyrannosaurine Gorgosaurus to a wide audience of professionals and amateurs. Following the symposium, Dave joined in the expedition in search of the Spinops quarry. First, we hired a small room in a ‘Hotel and BBQ Pit’ in a little place called Patricia, a few miles outside Dinosaur Provincial Park. It is an old haunt of Canadian palaeontologists and the accommodation could best be described as offering ‘substantial scope for improvement’. I experienced for the first time in many many years the joys of an upper bunk bed! But it all added to the fun and, as the name suggested, in the evening guests get to cook their own steaks, burgers and chicken on a big indoor barbeque. We were all up early the following morning and after a hot breakfast we set off for the field with pack lunches and plenty of water as the weather, which had been cold with snow flurries, had turned quite warm and windy. Darren had arranged access with a land owner and we drove across the prairie in search of a padlocked fence that we had been given the combination to. The terrain was incredibly flat and featureless but thanks to Darren’s knowledge and a bit of help from the GPS, we found our way. En-route we saw some great wildfowl and white tailed deer which gave Dave an opportunity to get busy with his telephoto lens. Hoodoo Soon enough we reached a point where the prairie fell suddenly away into coulees and down into the Red Deer River Valley with the great bluffs of the Upper Cretaceous rising all around. This landscape was formed after glaciers scraped away  great swathes of land during the last ice age 13,000 years ago and has been steadily eroding ever since, creating some wonderful capped pinnacles called hoodoos, where ironstone rich layers weather out atop columns of softer sandstone rocks, like giant m

Just remember. You have nothing to hide, right?

The systematics of Late Jurassic tyrannosauroid theropods from Europe and North AmericaAuthors:1. Stephen L. Brusatte (a,b,c)2. Roger B.J. Benson (d,e,f)Affiliations:a. Division of Paleontology, American Museum of Natural History, Central Park West at 79th St., New York, NY, 10024, USAb. Department of Earth and Environmental Sciences, Columbia University, New York, NY, USAc. School of GeoSciences, The University of Edinburgh, Grant Institute, The King's Buildings, West Mains Road, Edinburgh EH9 3JW, UKe. Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ, UKf. Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UKg. Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, UKAbstract:Recent discoveries of more than ten new species of tyrannosauroid theropods are helping to understand the origin and evolution of colossal body size and other characteristic features of Tyrannosaurus rex and its terminal Cretaceous relatives. Particularly important has been the discovery and reinterpretation of Late Jurassic tyrannosauroids from Europe and North America, which are intermediate in size and phylogenetic position between small basal tyrannosauroids and the largest Late Cretaceous species. The fragmentary nature of these Jurassic specimens, however, has frustrated attempts to understand their systematics and phylogeny. A new specimen from the Late Jurassic of England was recently named as a new species (Stokesosaurus langhami) of the genus Stokesosaurus, which is known from several fragmentary fossils from North America. We review the systematics and phylogeny of these European and North American specimens and show that there are no unequivocal synapomorphies uniting them. Furthermore, a revised phylogenetic analysis does not recover them as sister taxa. This necessitates a taxonomic revision of this material, and we name a new genus (Juratyrant) for the British specimen.

As you might have already guessed, the Tyrrell is not short of tyrannosaurs and this blog is going to be heaving with them by the end. I mean, this is the second post and I’m still on all the life reconstructions! (and no, we’ve not got to the murals yet, let alone the actual mounts and specimens). First off is this great rendering which stands outside at the main entrance, and it’s one I really like and probably prefer to the set I covered in the last post. The pose is really cool and a colours are great (though perhaps a bit faded in the sun), but it really is a great way to welcome people to the museum and stands atop the Tyrrell logo which is, well, you guessed. The second one is not easy to see as it’s in the education centre and so not always visible to the average visitor, which is a shame as it is absolutely great. It looks like a bronze statue from a distance, but in fact appears to be made of metal plates welded together, with the details picked out with blobs of metal that I assume were welded or soldered on. It’s mounted on a plinth with seats built into one side, and a glass case containing a partial skull on the other. While it’s a shame not everyone gets to see these, I’m sure it’s a real thrill for the kids that they get to see some bonus stuff the adults can’t and it’s a superb sculpt. I’m not sure I’ve ever seen anything quite like it, and welding can’t be the easiest medium, yet the result is brilliant. Coming next? Oh, I don’t know. I still have several hundred images to sort through and much exam marking to complete. I’m sure I can find something exciting though. Probably with tyrannosaurs, whether I intend to or not.

Alternative interpretations of some earliest Ediacaran fossils from ChinaAuthors:1. Heyo Van Iten (a)2. Juliana De M. Leme (b)3. Antonio C. Marques (c)4. Marcello G. Simões (d)Affiliations:a. Department of Geology, Hanover College, Hanover, IN 47243, USAb. Department of Sedimentary and Environmental Geology, University of São Paulo, 05580-080, São Paulo, SP, Brazilc. Department of Zoology, University of São Paulo, Rua do Matão, Travessa 14, 101, 05508-090, São Paulo, SP, Brazild. Department of Zoology, São Paulo State University, 18.618-000, Botucatu, SP, BrazilAbstract:In a letter to Nature (February, 2011), Xunlai Yuan and collaborators recorded carbon compression fossils from black shales of the Lantian Formation (Ediacaran), southern Anhui Province, South China. The new fossils, described under five morphological types (Types A to E), exhibit degrees of morphological differentiation suggesting that they were multicellular eukaryotes. Some of the Lantian macrofossils were interpreted as algae, but others are of unknown affinities. For reasons noted in this discussion, Type A fossils attracted our particular attention, and we suggest an alternative interpretation of their affinities. According to our view, some of them (at least those with three faces and no globose holdfast at their base) may represent conulariid cni?darians or close medusozoan relatives. The undistorted organism probably was a three?sided cone in life. We believe that our suggested alternative interpretations of the anatomy and affinities of the fossils in question can be useful in guiding future research on the oldest currently known fossil assemblage of multicellular organisms.

Just finished a sort of long-term new project for us. Occasionally we get requests from museums and universities to come out in the field with us and collect specimens. Even more occasionally, we oblige. In 2011 a class from the University of Tennessee - Martin (actually 2 classes, one in geology, one in journalism) came out to our digsites in western Kansas to find and document fossils for a new museum project. TPI fieldcrews supervised and instructed, however we let the students do the finding. They came up with several neat little fossils (several Spinaptychus, a Chelosphargus partial skull, Martinichthys skulls) and lots of partial fish. On the second day, one student hit the jackpot: the tip of the lower jaw of a mosasaur poking out from just under the alluvium. Ever feel like you're being watched?Here, Aaron (the discoverer) works to remove overburden from the specimen. TPI does the same thing, though usually with fewer spectators. He decided to name the mosasaur "Kimberly". I've named specimens worse things I suppose.Digsite viewed from across the gully, right near MU 5 The specimen was tentatively identified int he field as Platecarpus planifrons. Though reasonably well articulated, it was missing the front limbs and everything back behind the mid dorsal vertebrae. UTM students preimetered, stabilized and jacketed the specimen. Most importantly they also carried the slab across the badlands to the nearest truck, which was great for me!Standard TPI field photo pose, before jacketingBack in the lab, preperation was begun by UTM students under TPI guidance. Mosasaurs are usually pretty straightforward to work with, however this one presented a few challenges. The proximity to the alluvium meant that this specimen encountered some weathering back during the last ice age, and roots made matters worse. The prognosis was grim initially, as the bone and teeth looked to be in pretty rough shape. But careful consolidation and prep resulted in not only stable bone, but the discovery of the preserved remnants of tracheal rings, as well as extracollumnellar (ear) cartilage. At the rear of the left lower jaw, one of the scavenging sharks, Squalicorax falcatus, left its calling card.Kimberly's skullNext up the specimen will be delivered to the new museum in Tennessee, where it will go on display later this year. Luckily the whole process was documented by the journalism students, almost from the instant of discovery. If I see the video, I'll post a copy on the blog in the future.Not a bad little mosasaur.

New material and reinterpretation of the Late Cretaceous eutherian mammal Paranyctoides from UzbekistanAuthors:1. Alexander O. Averianov (a)2. J. David Archibald (b)Affiliations:a. Zoological Institute, Russian Academy of Sciences, Universitetskaya nab. 1, 199034, Saint Petersburg, Russiab. Department of Biology, San Diego State University, San Diego, California, 92182-4614, USA.Abstract:Paranyctoides aralensis, based on a partially known set of lower postcanines from the Turonian Bissekty Formation of Uzbekistan, is proposed to be a junior subjective synonym of Sailestes quadrans, itself based on an M1 from the same stratigraphic unit. As a result, the latter taxon is recombined as Paranyctoides quadrans comb. nov. Based on newly collected or recognized specimens, we show that this species has four lower incisors, including a procumbent i1 and a relatively small i4, as well as five double?rooted premolars, the smallest of which (p3) can be lost ontogenetically. The p5 of this species is premolariform, rather than molariform as previously thought based on an erroneous identification, and resembles North American species of Paranyctoides in the presence of a small, cingulid?like paraconid and a distal talonid cusp, as well as the absence of a metaconid. The lower molars of Paranyctoides are unique among Late Cretaceous eutherians in having a larger, lingually placed paraconid. Paranycoides probably is the sister taxon of the Late Cretaceous Zhelestidae.

Juvenile-only clusters and behaviour of the Early Cretaceous dinosaur PsittacosaurusAuthors:1. Qi Zhao (a,b)2. Michael J. Benton (a)3. Xing Xu (b)4. Martin J. Sander (c)Affiliations:a. School of Earth Sciences, University of Bristol, Bristol BS8 1RJ, UK ab. Key Laboratory of Evolutionary Systematics of Vertebrates, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, PO Box 643, Beijing 100044, Chinac. Division of Paleontology, Steinmann Institute, Rheinische Friedrich-Wilhelms-Universität Bonn, Nussallee 8, D-53115 Bonn, Germany.Abstract:It has hitherto been hard to prove that any association of juvenile dinosaurs represents original behaviour rather than sedimentary accumulation, and it has been hard also to determine the ages of such juveniles. A previously described specimen, which consists of an ‘adult’ Psittacosaurus with 34 fully articulated juveniles, turns out to be a composite: the ‘adult’ skull has been added, and in any case it is below breeding age. Other juvenile-only clusters have been reported, but the best examples that likely reflect behaviour rather than sedimentary accumulation are specimens from the Early Cretaceous Lujiatun beds in NE China, which were entombed beneath pyroclastic flow deposits. A remarkable juvenile-only cluster of Psittacosaurus shows clear evidence of different ages (five 2-year olds and one 3-year old) based on bone histological analysis. These juveniles may have associated together as a close knit, mixed-age herd either for protection, to enhance their foraging, or as putative helpers at the parental nest.

An ankylosaurid dinosaur from Mongolia with in situ armour and keratinous scale impressionsAuthors:1. Victoria M. Arbour (a)2. Nicolai L Lech?Hernes (b)3. Tom E Guldberg (c)4. Jørn H Hurum (d)5. Phillip J Currie (a)Affiliations:a. Department of Biological Sciences, CW 405 Biological Sciences Building, University of Alberta, Edmonton, Alberta, Canada, T6G 2E9b. Bayerngas Norge, Postboks 73, N?0216 Oslo, Norwayc. Fossekleiva 9, N?3075 Berger, Norwayd. Natural History Museum (Geology), University of Oslo, Postboks 1172 Blindern, N?0318 Oslo, NorwayAbstract:A Mongolian ankylosaurid specimen identified as Tarchia gigantea is an articulated skeleton including dorsal ribs, the sacrum, a nearly complete caudal series, and in situ osteoderms. The tail is the longest complete tail of any known ankylosaurid. Remarkably, the specimen is also the first Mongolian ankylosaurid that preserves impressions of the keratinous scales overlying the bony osteoderms. This specimen provides new information on the shape, texture, and arrangement of osteoderms. Large flat, keeled osteoderms are found over the pelvis, and osteoderms along the tail include large keeled osteoderms, elongate osteoderms lacking distinct apices, and medium?sized, oval osteoderms. The specimen differs in some respects from other Tarchia gigantea specimens, including the morphology of the neural spines of the tail club handle and several of the largest osteoderms.

RECONNAISSANCE OF THE HR 8799 EXOSOLAR SYSTEM. I. NEAR-INFRARED SPECTROSCOPYAuthors:1. B. R. Oppenheimer (a) 2. C. Baranec (b) 3. C. Beichman (a,c) 4. D. Brenner (a) 5. R. Burruss (d) 6. E. Cady (d) 7. J. R. Crepp (e,m) 8. R. Dekany (b)9. R. Fergus (f) 10. D. Hale (b) 11. L. Hillenbrand (e) 12. S. Hinkley (e) 13. David W. Hogg (g) 14. D. King (h) 15. E. R. Ligon (d) 16. T. Lockhart (d) 17. R. Nilsson (a)18. I. R. Parry (a,h)19. L. Pueyo (i) 20. E. Rice (a,j)21. J. E. Roberts (d) 22. L. C. Roberts, Jr (d) 23. M. Shao (d) 24. A. Sivaramakrishnan (a,k)25. R. Soummer (a,k) 26. T. Truong (d) 27. G. Vasisht (d) 28. A. Veicht (a) 29. F. Vescelus (d) 30. J. K. Wallace (d) 31. C. Zhai (d) 32. N. Zimmerman (a,m)Affiliations:a. Astrophysics Department, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024, USA; bro@amnh.orgb. Caltech Optical Observatories, California Institute of Technology, Pasadena, CA 91125, USAc. NASA Exoplanet Science Institute, California Institute of Technology, Pasadena, CA 91125, USAd. Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena CA 91109, USAe. Department of Astronomy, California Institute of Technology, 1200 E. California Blvd, MC 249-17, Pasadena, CA 91125, USAf. Department of Computer Science, Courant Institute of Mathematical Sciences, New York University, 715 Broadway, New York, NY 10003, USAg. Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place, New York, NY 10003, USAh. Institute of Astronomy, Cambridge University, Madingley Road, Cambridge CB3 0HA, UKi. Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218, USAj. Department of Engineering Science & Physics, College of Staten Island, 2800 Victory Blvd., Staten Island, NY 10314, USAk. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USAl. unknown, not included in paper.m. unknown, not included in paperAbstract:We obtained spectra in the wavelength range ? = 995–1769 nm of all four known planets orbiting the star HR 8799. Using the suite of instrumentation known as Project 1640 on the Palomar 5mHale Telescope, we acquired data at two epochs. This allowed for multiple imaging detections of the companions and multiple extractions of low-resolution (R ? 35) spectra. Data reduction employed two different methods of speckle suppression and spectrum extraction, both yielding results that agree. The spectra do not directly correspond to those of any known objects, although similarities with L and T dwarfs are present, as well as some characteristics similar to planets such as Saturn. We tentatively identify the presence of CH4 along with NH3 and/or C2H2, and possibly CO2 or HCN in varying amounts in each component of the system. Other studies suggested red colors for these faint companions, and our data confirm those observations. Cloudy models, based on previous photometric observations, may provide the best explanation for the new data presented here. Notable in our data is that these presumably co-eval objects of similar luminosity have significantly different spectra; the diversity of planets may be greater than previously thought. The techniques and methods employed in this paper represent a new capability to observe and rapidly characterize exoplanetary systems in a routine manner over a broad range of planet masses and separations. These are the first simultaneous spectroscopic observations of multiple planets in a planetary system other than our own.