Paleo-News 7
*POOF* Woah, where am I? I'm back on dA?! That must mean all my school work is done! 
Or I'm procrastinating. 
Either way, looks like we're long overdue for some Paleo-News! 
Many have long suspected that Stegosaurus longispinus was worthy of its own genus, separate from the better known S. stenops. The problem is we don't very much to go off of because most of the material was destroyed by water damage. But a new study was able to find photos of the original specimens (it's Spinosaurus all over again!) and confirm that the remains did not belong to a species of Stegosaurus, instead they erected a new taxon, Alcovasaurus longispinus. This strikes down the name "Natronasaurus" proposed by Ulansky a while back; the authors found his publication(s) did not meet the standards of the ICZN, rendering all of his proposed names (at least 17) invalid. It's about time!!! 
A study on the forelimbs of Oryctodromeus found that it was exceptionally well adapted for burrowing.
A new juvenile Pachycephalosaurus specimen has features very much like those of "Dracorex", casting additional doubt onto the validity of the latter.
The sail-finned fish Pentanogmius is well known from the Western Interior Seaway, and now a new species gets to show off its elaborate finnage. P. fritschi's sail-fin was hook shaped up front, kind of like Jessie's hairdo from Team Rocket!
Two new species of the large Cretaceous filter-feeder Rhinconichthys, R. purgatorensis and R. uyenoi, are described from the US and Japan, respectively. Their well preserved skulls revealed that an odd arrangement of their jaw bones allowed them to open their mouths extra wide.
Herreraichthys coahuilaensis, a marine Late Cretaceous gar, is described from Mexico.
The new Mid-Triassic stem-neopterygian Venusichthys comptus exhibits obvious sexual dimorphism, hinting at a unique breeding strategy.
The post-cranial anatomy of the notosuchian Caipirasuchus is published.
The first definitive atoposaurid remains from the Middle Jurassic are published.
Mekosuchian behavior and appearance is explored in a new study that found that their vertebrae were unusually short, suggesting that these crocodilians were probably proportionally shorter bodied than living crocs. The implication is that this rendered them unable to perform a "death roll", meaning they likely dismembered prey in other ways, such as with powerful neck muscles or with their forelimbs.
A new 5 meter long abelisaurid Viavenator exxoni is described from Argentina, being known from most of its vertebrae, ribs, and part of the skull.
A study on archosaur skull sutures found that they were ontogenically variable in among living species. Emu sutures close to sexual maturity, but those alligators actually become wider. The authors conclude the closure of skull sutures has more to do with biomechanics than maturity.
Beautiful Mesozoic butterfly-like lacewings are described as early pollinators.
The feeding strategy of the odd marine "bear" Kolponomus is investigated. A review by Brian Switek sheds a bit more light than the pay-walled paper.
A new study on the recent extinction of Australian megafauna suggests, once again, that humans were primarily to blame. This paper goes into greater depth than many previous ones on the topic.
A Middle Jurassic herbaceous angiosperm from China has some serious implications for the evolution of the group. (Warning: paper takes forever to load!)
The histology of juvenile Psittacosaurus is explored, revealing that the young were likely precocial and that they grew slower than the young of large ornithischians.
BANDits! They're at it again, this time trying to debunk Ornithomimus feathers which the author claims to be collagen fibers. Certainly not their most original idea... Naturally, the original authors responded swiftly.
Remains of Gastornis and a presbyornithid have been found in Eocene rocks from the high Arctic, demonstrating just how warm the place was back then.
New material from the Mongolian Elmisaurus and the North American Leptorhynchos is described. Still haven't fixed the latter's name though. 
A small abelisaurid from Argentina is described, but not named. It's about the same size as Viavenator, but a bit more primitive.
Evidence of a failed attack on a Hesperornis by a polycotylid plesiosaur is described.
A new study suggests that the Jurassic – Cretaceous transition had far more casualties than previously believed.
Ontogeny is certainly one of the big topics in dinosaur paleontology right now, despite the fact that it's a messy field with many ill-defined terms. A new paper aims to bring this into focus so that we're all on the same page. An additional article by one of the authors will be of interest.
Another paper on dino ontogeny, this time focusing on Majungasaurus skull growth. Like I said, it's a popular subject.
A new paper on Early Cretaceous termites helps fill in the gaps of social insect evolution.
An unnamed freshwater teleosaurid is described from an excellently preserved skull. It expands the known ecology of thalattosuchians.
A new study casts doubt on the validity of Stegoceras “novomexicanum”, finding strong evidence that it is likely a juvenile of another species.
The ichthyosaur Stenopterygius appears to have exhibited an ontogenic niche shift, switching from small fish to larger fish and cephalopods upon maturity. Fully mature animals may have only preyed on cephalopods.
Everything you ever wanted to know about Chinese pareiasaurs!!!
The Cretaceous sediments of Tunisia exhibit an usually high level of lungfish diversity. This new paper suggests that such diversity is a result of the depositional environment, with at least some remains having been washed downstream from inland environments.
New specimen of Cretaceous mosquitos preserved in amber reveal that they are, as scientists suspected, members of the living crown-group. No word yet on their potential for cloning dinosaurs...
It's always nice when people embrace their local natural history, and the people of Chernyshevsky, Russia, have done just that by adding Kulindadromeus to their new coat of arms and flag! 
A study demonstrated that the number of plants that exhibit polyploidy increases dramatically after the K/Pg event.
A redescription of the large mosasaur Hainosaurus found that its supposedly distinct characters are not as distinct as originally thought. The genus is therefore lumped into Tylosaurus, as the distinct species T. bernardi.
Of course, we're all now familiar with Fukuivenator paradoxus, the odd maniraptoriform theropod from the Early Cretaceous of Japan. Analyses by Cau and Mortimer found it to be a bit more derived than the original authors, nesting somewhere near the base of pennaraptora (oviraptorosaurs + paraves), but still really strange.
New specimens of the ornithischian Haya have been recovered from Mongolia.
Numerous pathologies were found on a forelimb belonging to Dilophosaurus, the most found in any single dinosaur limb.
An exciting new Jurassic site in Argentina shows incredible levels of fossil preservation. I'm sure it'll only be a matter of time before something really cool in uncovered there!
The Oligocene and Miocene bird Wilaru, previously thought to be a stone-curlew, is reidentified as the youngest presbyornithid. W. prideauxi is the newly named species and indicates not only the presence of presbyornithids in Australia, but also that some taxa exhibited unique terrestrial adaptations. The Late Cretaceous Mongolian bird Treviornis is also confirmed as a member of the group, showing all of the characteristics interpreted as basal to presbyornithids.
A portion of a good-sized abelisaur femur is described from the Kem Kem, along with a summary of large theropod remains from the region. The accompanying life restoration sparked interesting debate regarding what we do and do not know about abelisaur integument (be sure to read the comments!). This further led to discussion regarding the “quill nodes” of Concavenator.
A new Argentinian titanosaur nest site suggest multiple types of titanosaurs nested in the same area but avoided competition by burying their eggs in slightly different ways/places.
The existence of intact dinosaur blood vessels has been a matter of controversy, but this new research demonstrates that the organic material observed was certainly not left behind by microorganisms' biofilms.
A study on the growth of the dinosauriform Asilisaurus found no strong correlation between size and maturity. This suggests that alleged size related sexual dimorphism in certain early dinosaur may be related to ontogenic factors instead.
The same scientists that wish to clone a mammoth have also turned their gaze toward Cave lions. They hope to use the recently found cubs preserved in permafrost. Sounds like a much more achievable goal than a mammoth. Note to self: don't tell these guys about the Cretaceous mosquitoes! 
The recently extinct Pink-headed Duck got its namesake color from carotenoids, a true rarity among waterfowl. This suggests carotenoid use can pop up pretty much anywhere provided the diet contains enough of them, and that includes in non-avian dinosaurs. *insert image of pink Deinocheirus*
The extinction of ichthyosaurs is one of paleontology's greatest mysteries, but a new study suggests that sudden climate and oceanic changes in the Mid-Cretaceous coupled with their reduced diversity led to their demise.
Another group that faced a time of crisis was crocodyliformes at the J/K boundary. This in depth study reveals that fluctuating sea levels and the resultant tampering with chemical cycles led to the sudden demise of many species. In the aftermath, the lessened ecological pressure allowed for the evolution of modern crocodilians and notosuchians.
Six species hesperornithiformes are identified from a site in Manitoba, Canada, including a new species: Hesperornis lumgairi.
An assessment of the flightless mihirungs (demon-ducks-of-doom) also describes a new species: Dromornis murrayi.
And finally, a super cool study on a dozen different lizards preserved in 99 million year old amber from Myanmar. They include a stem-squamate with an unusual tongue, a basal gecko, a lacertoid, a crown agamid, a possible scincomorph, and the oldest chameleon ever found! The latter is especially important, as chameleon fossils are almost unknown, let alone one preserved in amber! It shows many of the same skull features as modern chameleons, including a short snout and big orbits, and it probably had a long tongue to shoot at prey. Otherwise, it would've looked like any other tiny lizard, except for its small curled tail and spindly legs. It had yet to evolve the specialized feet, laterally compressed body, or ornamentation of modern chameleons. Be sure to download the video in the supplemental data to see the 3D CT scans!
Off to the Desert!
Wish me luck!
Paleo-News 6
A new phylogenetic analysis of aetosaurs helps sort out the mess of very similar taxa and introduces a new one, Scutarx deltatylus.
The deserts of Tunisia sound like they're well on there way to being the next Kem Kem Beds of Morocco, complete with giant crocodiles! Meet Machimosaurus rex, at 10 meters, is the largest and youngest teleosaurid known. Further recommended reading by Andrea Cau (one of the authors) here, here, and here. While this giant prowled the waterways, the land was trodden by iguanodonts.
A new study on early rhynchosaurs helps resolve the relationships of the group and introduces a new taxon, Langeronyx brodiei. Lots of good photos in the paper!
Liniyornis amoena, a new genus of enantiornithe from China, preserves traces of an ovary, thus giving us that rare opportunity to declare the specimen a female with absolute certainty.
A new Chinese ornithuromorph, Dingavis longimaxilla, is notable for its elongated rostrum and close resemblance (synonym?) to the poorly described Juehuaornis.
An abelisaurid specimen from Brazil shows evidence of pneumatization.
Eotrachodon orientalis is a new basal euhadrosaur close to the origin of saurolophines and lambeosaurines. More excitingly, it's known from most of its skull and a good portion of its skeleton. Even more excitingly, its from Appalachia, suggesting hadrosaurids may have originated there before spreading to Laramidia and Eurasia.
Nasutoceratops is described in detail and found to form a clade with Avaceratops, suggesting a previously unknown group of centrosaurines may have occurred throughout the American west.
Protoceratops frills show evidence for positive allometry with growth, furthering the notion that these structures were involved in sexual selection.
A study on the dentary groove in tyrannosaurs recovers Nanotyrannus as, not only a valid genus, but as a member of the albertosaurines. But don't get too excited, turns out the paper is an example of some pretty sloppy science.
A track site from Korea preserves excellent ornithopod tracks, but also reportedly contains traces of a theropod tail drag! Given the Early Cretaceous age and lake-side paleoenvironment, I wonder if these tracks could have been left by a tail-dragging spinosaur.
A new aristonectine plesiosaur from New Zealand, Alexandronectes zealandiensis, is among the smallest of its group.
Confirming what we've long suspected, a new paper establishes that the pterosaur fossil record and its diversity is absolutely controlled by preservational bias.
An excellently preserved tyrannosaur trackway provides info on walking speed and stride length.
A specimen of Plotosaurus from Chile suggests that mosasaur distribution was more closely linked to prey availability than temperature.
Yet another gigantic titanosaur from Argentina, Notocolossus gonzalezparejasi, is described. While the entirety of the animal isn't very complete, it does give us the best glimpse yet at what the hind foot of these titans looked like.
Remember that Early Jurassic Welsh theropod mentioned a while back? It has now been described! Say hello to Dracoraptor hanigani, an apparent relative of Tawa and other basal neotheropods.
A cute, and very complete, little baby Chasmosaurus is described and helps shed some light on how big ceratopsians aged. The phylogenetic analysis highlights the importance of knowing when to score characters as juvenile characteristics.
An ornithomimid limb from Kazakhstan helps fill in our knowledge of this little known region.
A study on palaeognath bird melanosomes finds that melansomes are pretty variable across neornithes in terms of what colors their shapes can represent. It means fossil melanosomes may not always equal the we think they would in the living animal.
Mark Witton wrote an excellent article on everyone's favorite dino-cruncher (or should that read turtle-cruncher...), Deinosuchus.
A new study suggests that the limbless amphisbaenian lizards had a Late Cretaceous origin.
Chongmingia zhengi, a new basal bird from, wait for it, WAIT FOR IT..... China, is described (insert discussion on how everything is made in China these days). It's missing its skull and tail, so it's hard to say what it looked like, but it appears to have been either slightly less derived than Jeholornis (really basal) or just basal to the split between enantiornithes and ornithuromorphs.
Also on the subject of birds, a new preprint paper tries to reconcile how flapping, and thus primary feathers, may have originated in dinosaurs. The authors conclude that locomotion was likely not a primary driving factor in the original evolution of wings.
wrote a great article on the research history and implications of our recent best friend Kulindadromeus, or the Kulinda Ornithischian (KO), if you prefer.A must-have paper covering the systematics of rubidgeinae gorgonopsids!!! It's packed with skull reconstructions of little known and sometimes quite strange species!
A novel form of sauropod neck pathology.
The paper on the recent new bird Bellulia is now open access.
The Late Cretaceous Iberian Peninsula appears to have had rather high sauropod diversity.
A new paper highlights the speed potential of various macropredatory theropods (why exclude non-predatory ones is beyond me) based on limb proportions. Notable conclusions were that dromaeosaurs were rather slow for their size and Nanotyrannus is posited as the fastest of the meat-eaters tested. The authors note that while juvenile albertosaurines tested close to adults, Nanotyrannus and Tyrannosaurus were nowhere near each other. It's worth pointing out that no other juvenile tyrannosaurines were tested in the study, so it's too early to say if the result is phylogenetically significant.
Meroktenos thabanensis, a new sauropodomorph from Lesotho, is described from reexamined material of Melanorosaurus.
New material from Prestosuchus from Brazil helps fill in its ontogenic sequence.
A new study hints at the ecological relationships between abelisaurs, carcharodontosaurs, and spinosaurs in Thailand.
Bayesian analysis is applied to tyrannosauroids for the first time. The results are largely congruent with previous studies, but with higher support values and a few surprises. Bistahieversor is found to fall just outside of tyrannosauridae, alioramini falls within tyrannosaurinae and also includes Dryptosaurus among its ranks!
Haimirichia amonensis is a peculiar new Cretaceous lamniforme shark with a very wide distribution and a very blunt Tiger Shark-like snout.
A new mature specimen of Archaeorhynchus demonstrates that early ornithuromorphs grew more slowly than modern birds, similar to other basal birds.
The skull of the archosaur Riojasuchus is studied in detail.
And finally, a bonebed of the wildebeest relative Rusingoryx not only helps resolve the sexual and age related differences in this taxon, but also shows it possessed a nasal structure shockingly similar to lambeosaurine hadrosaurs!!!
Oh, and something to be on the lookout for. While scrolling through a paper on Nature, this appeared on the "Up Next" list at the top of the page: "A bizarre theropod from the Early Cretaceous of Japan highlighting mosaic evolution among coelurosaurians Sci Rep, 2016". Sounds really intriguing, but clicking the link just led me to an error-404 page. Hopefully it's going to be published shortly!
TPA 2015 Highlights
Five new Tournaisian tetrapods: their sedimentology and palaeoenvironments
Carys E. Bennett1, Jennifer A. Clack, Timothy Kearsey, Sarah J. Davies, David Millward, Tim R. Smithson, Marcello Ruta, Ben Otoo, John E. A. Marshall, Emma Reeves and Andrew Ross
Far from being a depauperate interval for fossil tetrapods, the Tournaisian has recently yielded an unprecedented diversity of taxa. A cladistic analysis of five new tetrapod species places three taxa below the origin of the tetrapod crown group. The remaining two taxa are part of the amphibian stem group. The fossils occur spaced through the Ballagan Formation at the Burnmouth and Willie’s Hole sites. Despite their stratigraphic and geographic separation, four of the five tetrapods occur in the same lithology, a microconglomerate: matrix-supported grey siltstones with clasts of 1-2 mm in size derived from floodplain sediments. Microconglomerates are common (140 beds in a 490 metre succession), often (71% of beds) overlying desiccation cracks, and are one of the richest fossil deposits in this formation; plant fossils and megaspores are abundant as are the remains of actinopterygians, rhizodonts, ostracods, eurypterids, myriapods and non-marine bivalves. Tetrapods, lungfish and chondrichthyans are rarer. Deposition occurred in seasonal flooding events, likely due to monsoonal rainfall. Varied palaeosols and palynology indicate a mosaic of environments including forests, scrubland, wetlands and desiccating pools. Fossil specimens are often articulated and indicate minimal transportation and rapid burial. These under-recognized deposits record early diversification of tetrapods into newly-appearing habitats.
Sounds like some important fossils are set to come from this locality.
The Strawberry Bank Lagerstätte reveals insights into Early Jurassic life
Michael J. Benton, Matt Williams, Andrew Ross and Matt Friedman
The Strawberry Bank Lagerstätte from the Early Jurassic (early Toarcian) of Ilminster, Somerset, provides a rich insight into Early Jurassic marine vertebrate life, revealing exquisite anatomical detail of marine reptiles and large pachycormid fishes thanks to exceptional preservation, and especially the uncrushed, 3D nature of the fossils. The site documents a fauna of Early Jurassic nektonic marine animals (five species of fishes, one species of marine crocodilian, two species of ichthyosaurs, cephalopods and crustaceans), but also over 20 species of insects. Unlike other fossil sites of similar age, the 3D preservation at Strawberry Bank provides unique evidence on palatal and braincase structures in the fishes and reptiles. The age of the site is important, documenting a marine ecosystem during recovery from the end-Triassic mass extinction, but also exactly coincident with the height of the Toarcian oceanic anoxic event, a further time of turmoil in evolution. Initial digital reconstructions show the great potential of the site, and a new, funded project aims to extract full information from this long-forgotten Lagerstätte.
Ooh, if delicate insect fossils are preserved here, it makes me wonder what else is possible. Early Jurassic feathered dinos perhaps?
Remarkably preserved brain tissue ultrastructure in an Early Cretaceous iguanodontian dinosaur
David B. Norman, Martin D. Brasier, Alexander G. Liu, Laura Cotton, Jamie Hiscocks, Russell Garwood and David Wacey
We report high-fidelity mineralization of soft tissues within a natural cranial endocast of an iguanodont dinosaur from fluvial sediments of the Wealden (Hastings Group) in Sussex. Moulding of the braincase wall and adjacent brain tissues by phosphates and carbonates allows direct examination of fossilized brain tissue, arguably for the first time in the fossil record. SEM imaging and CT-scanning reveal ultrastructural preservation of the membranes that surrounded the brain itself (meninges) and larger blood vessels are preserved in collophane (calcium phosphate), and the vessels are either lined by, or infilled with, microcrystalline siderite (iron carbonate). Meninges of the cerebellum preserved in this specimen exhibit ultrastructural similarities with those seen in living archosaurs. In addition, some of the fabric of the outer cortical layers of the brain and associated smaller blood vessels are also preserved in phosphate and carbonate. The structure of these membranes and associated tissues has some bearing on the extent to which the brain filled the endocranial cavity and therefore upon estimates of encephalization quotients (EQs) in these dinosaurs. Implied behavioural repertoires derived from functional and biological inferences drawn from trace fossils among iguanodontian ornithopods are compared and contrasted with brain volume observations based upon this new specimen.
Now we’re really starting to get into their heads!
Evidence for sexual dimorphism in the plated dinosaur Stegosaurus mjosi (Ornithischia, Stegosauria) from the Morrison Formation (Upper Jurassic) of Western USA
Evan T. Saitta
Dimorphism in the shape of Stegosaurus mjosi dermal plates (n=40) does not result from non-sex-related individual, interspecific, or ontogenetic variation and is most likely a sexually dimorphic feature. One morph possessed wide, oval plates 45% larger in surface area than the tall, narrow plates of the other morph. Intermediate morphologies are lacking. Principal component analysis supports marked size- and shape-based dimorphism. In contrast, non-sex-related individual variations often show intermediate morphologies. A new quarry in Montana shows at least five individuals buried in a single horizon that were not brought together by water transportation. This site demonstrates co-existence, and possibly suggests sociality, between two morphs that only show dimorphism in their plates. Without evidence for niche partitioning, it is unlikely that the two morphs represent different species. Histology of the new specimens in combination with studies on previous specimens indicates that both morphs occur in fully-grown individuals. The dimorphism is not a result of ontogenetic change. The two morphs of plates do not come from different positions on the back of a single individual. Plates from all positions on the body can be classified as one of the two morphs, and previously discovered, isolated specimens possess only one morph of plates.
Sounds like a solid case for sexual dimorphism! If only ceratopsians were this easy to decipher.
How big is a genus?
Julia D. Sigwart, Keith D. Bennett and Mark Sutton
Genera are units that contain variable numbers of species, from one (monotypic) to thousands. The largest proportion of genera, usually over 30%, contain only a single species and a very small proportion contain large numbers of species. Past observations of this phenomenon have invoked taxonomic ‘splitting’, and implied this skewed distribution is in conflict with strict tree-thinking or true phylogenetic systematics. We show the predominance of monotypic genera is a strongly consistent pattern across Metazoa, so empirical evidence suggests it may be a ‘real’ result of speciation processes. We compared empirical data (real taxonomy of real organisms) with simulations that provide omniscient or ideal genus-size frequencies (simulated taxonomic sorting on simulated trees). We generated hypothetical trees using birth–death models with known and constant probabilities of speciation (birth) or extinction (death) at each generation. We imposed a taxonomic sorting on the set of species that were non-extinct after 500 generations, based on phylogenetic topology and/or character attributes of surviving lineages. Observed taxonomy of living animals in fact closely match an idealized hypothetical taxonomy of monophyletic units, especially when defined by character similarities. Monotypic genera are, as should be expected, very frequent, and large genera very rare (splitters 1, lumpers 0).
Boom! Shots fired!!!
Phylogeny and macroevolution of crocodylomorphs
Max T. Stockdale, Michael J. Benton, Mario Bronzati, Marco B. de Andrade and Gavin T. Thomas
The Crocodylomorpha present a unique dichotomy in their diversity and morphological disparity through time. The stem group is limited to the Mesozoic, but is represented by a highly disparate range of ecomorphologies. Conversely the crown group is limited to amphibious ambush predators, but is represented by a much greater species richness than the stem group. Despite the abundance of the crown group, the crown-group Crocodylomorpha are represented by just 23 extant species. Does this pattern represent a true decline in disparity and diversity through time, or a more complex sequence of shifts within the group? Here we present a comparison of evolutionary rates among crown- and stem-group Crocodylomorpha in relation to morphospace occupation. The phylogenetic framework of these analyses is a new phylogeny of the Crocodylomorpha assembled using the matrix representation parsimony (MRP) method. This study finds support for extreme evolutionary stasis in several crocodylomorph clades. Diversity among the Crocodylomorpha appears to be closely linked with temperature, with decreasing diversity in the Cenozoic closely matching global cooling. Additional morphospace occupation by stem-group Crocodylomorpha relative to the crown group is occupied by taxa originating from two discrete adaptive radiations in the Mesozoic, with disparity otherwise remaining constant throughout the Mesozoic and Cenozoic.
So mammals probably aren’t what’s keeping crocodylians down, the temperature is.
Camouflage patterns in an ornithischian dinosaur
Jakob Vinther, Robert Nicholls, Stephan Lautenschlager, Gerald Mayr, Emily Rayfield and Innes Cuthill
Countershading is one of the most widespread forms of camouflage. A dark dorsum and light ventrum counteract the gradient created by illumination from above, obliterating cues to 3D shape. Because the optimal countershading varies strongly with light environment, pigmentation patterns give clues to an animal’s habitat. Melanosomes are preserved in feathered dinosaurs and aspects of original colour patterns can be reconstructed from these. Here we present a study of an exceptionally well-preserved specimen of Psittacosaurus from the Chinese Jehol biota, at the Senckenberg Museum. This Psittacosaurus was countershaded with a light underbelly and tail, while the chest is relatively more pigmented. Other pigmentary patterns resemble disruptive camouflage, while the chins and lateral horns on the face appear heavily pigmented. SEM analyses show that the impressions preserve small, spheroidal melanosomes, suggesting a brownish colour to the body. We have projected the colour patterns onto an anatomically correct lifesize model of Psittacosaurus in order to assess their function experimentally. These are compared to the predicted optimal countershading from the measured radiance patterns generated on an identical grey-scale model in direct versus diffuse illumination. These studies suggest that Psittacosaurus inhabited a closed habitat such as a forested area with a relatively dense canopy.
Very interesting! I thought it was once said to be impossible to detect melanosomes in scales. For the record, I believe this is the specimen they are referring to:
Two new odd Notosuchians from the Upper Cretaceous Bauru Group, Southeastern Brazil
Marco B. de Andrade, Rodrigo M. Santucci, William R. Nava
Notosuchian crocodylomorphs are a key element in South American Mesozoic fossil assemblages, particularly in the Upper Cretaceous fossil record of Bauru Group, where crocodylomorphs currently comprise over 15 taxa, most of them belonging to Sphagesauridae, Baurusuchidae and Peirosauridae. Undescribed specimens from the vicinity of Marilia, Brazil indicate the existence of two new notosuchian taxa. The first one – a small fragment of maxilla with teeth – comes from the Araçatuba/Adamantina Formations (Campanian) and represents a new species of the small-sized Adamantinasuchus, characterized by the presence of an antorbital fenestra. The second specimen – a partial skull and mandible – comes from the Marilia Formation (Maastrichtian). It represents a medium-sized sphagesaurid, displaying the typical dentition and morphology of this family, alongside unexpected bizarre characteristics of the rostrum, narial opening and orbital region. Most of the notosuchian fauna of Bauru Group contrasts with other South American and African crocodylomorphs, with dentition and skull morphology dedicated to process food rather than to capture prey. The continual increase of diversity and disparity of Brazilian fossil crocodylomorphs in recent decades suggests that the collection effort carried out since the 1940s has so far only provided a glimpse of the exquisite past faunal assemblages, particularly in the Bauru sediments.
The more weirdo crocs the merrier!
What were they thinking? Exploring the potential of neurocranial anatomical studies throughout Ceratopsia
C. Bullar, M. J. Benton, Q. Zhao and M. Ryan
The neurocranial anatomy of extinct organisms has always excited the palaeontological community. Since the 19th century, palaeontologists have been examining whether endocasts can provide a good resolution of brain size and morphology and, if so, what this can tell us about the sensory capacity of these long dead organisms. Ceratopsians were one of the most diverse dinosaurian clades of the Late Cretaceous and have a fantastic fossil record of basal forms in Asia. Ceratopsian palaeontology is currently lacking in comprehensive neuroanatomical studies. Analysis of ceratopsian neurological evolution will ultimately show how neurology likely affects behaviour, assumed through previous studies. This investigation offers the rare chance to study both basal Asian and North American taxa to enable analysis in a morphological and macroevolutionary context whilst creating an accessible set of braincase 3D PDFs. I present the preliminary study indicating what the palaeoneurology of Psittacosaurus lujiatunensis can tell us, and how this can be expanded to incorporate every major clade within Ceratopsia.
I wonder how this neurological info will compare with the study on its coloration and presumed habits.
A new specimen of Othnielosaurus consors
Armin Elsler, and Jürgen Kriwet
Here we describe a new specimen of Othnielosaurus consors from the Upper Jurassic Morrison Formation. The specimen was found at the Howe Stephens Quarry (Wyoming, USA) and represents the most complete and largest single skeleton currently known for this taxon. The postcranial skeleton is virtually complete except for the forelimbs, which are only partially preserved. The specimen exhibits the most complete cranial material (including a relatively well-preserved lower jaw and a right maxilla) found in a single individual of the taxon. The preservation quality of the bones varies from relatively well preserved to heavily crushed. Slight differences between this skeleton and other specimens referred to Othnielosaurus consors are noted, but are explained by either individual or ontogenetic variation or the preservation quality of the specimen. Whether the size difference in comparison with other specimens is related to ontogeny or sexual dimorphism cannot be determined currently. A phylogenetic analysis recovers Othnielosaurus consors with the new character scorings as a member of Neornithischia and sister taxon to Cerapoda. This result differs from earlier assessments, which referred to the taxon as a ‘hypsilophodontid’ or basal ornithopod, and is in agreement with relatively recent phylogenetic studies.
It’ll be interesting to see how much this taxon has in common in Kulindadromeus.
A new large-sized temnospondyl from the Permian of southern Brazil
Nubia Galvez, Marco B. de Andrade, and Rainer R. Schoch
Although the temnospondyl known diversity is substantial, the current knowledge of South American taxa is lacking. Remains of a large-sized temnospondyl from the Rio do Rasto Formation (Middle–Late Permian) of Southern Brazil represents a putative new taxon that may shed light on temnospondyl evolution and palaeobiogeography. The specimen MCP-4275PV is a hemimandible of ~50 cm in length, indicating that this specimen exceeded the majority of Brazilian temnospondyl taxa in size, only surpassed by the Late Permian Prionosuchus. Meaningful characters include a type I postglenoid area (PGA), hamate process and coronoids devoid of teeth, proportionally small but numerous dentary teeth. The short and posterodorsallyoriented retroarticular process parallels the morphology of certain Crocodylia, highlighting biomechanic similarities between these different tetrapod groups. Preliminary phylogenetic analysis (TNT, PAUP; 66 taxa, 217 characters) consistently places MCP-4275PV as the sistergroup of Parotosuchus, a capitosaur genus currently known from Laurasian territories, South Africa and Antartica. If confirmed as a Parotosuchus, MCP-4275PV will expand the presence of the genus to South America. Furthermore, it will represent possibly the oldest capitosaur, a group almost entirely restricted to the Triassic. The future use of CT-scanning should provide access to new morphological data and the refinement of current results.
It seems the broad snouted temnospondyls may have occasionally reached the giant sizes of the slender snouted varieties.
Adaptive radiation of marine crocodylians following the end-Cretaceous extinction
Polly Russell and Nick Longrich
The Gavialoidea, including Gavialidae and Tomistominae, are crocodilians typically recognized by their specialized snout morphology. The long, tubular (longirostrine) snout is a derived adaptation for piscivory, observed convergently in multiple crocodilian lineages. Existing fossils show this morphology to be highly conserved amongst Gavialoidea. Here we present new fossil material from the Paleocene deposits of Morocco that reveals unprecedented levels of disparity in skull shape, indicating that the gavialoid taxa staged a major opportunistic radiation in the aftermath of the K/Pg extinction. The new material includes four species. The first, a new Maroccosuchus species, exhibits robust bullet-shaped teeth and broad, blunt snout, seemingly suited for durophagy. The second, a new species of Argochampsa, shows a uniquely shortened snout and a reduced tooth count. The third is a new genus of small gharial. The fourth has a tooth count at least 50% greater than any known gharial species, with laterally projecting teeth and a hyper-elongate snout. This high disparity in the aftermath of the K/Pg extinction is mirrored in another clade of longirostrine, marine crocodilians – the Dyrosauridae. This suggests a more widespread opportunistic radiation of marine reptiles in the Paleocene, exploiting niches vacated by mosasaurs and plesiosaurs after the K/Pg extinction.
A saw-snouted gharial on the horizon!? Now I’m imagining large marine crocodiles fighting early whales in the surf!
Cracking dinosaur endothermy: palaeophysiology unscrambled
Max. T. Stockdale, Michael. J. Benton and Octávio Mateus
The amniote eggshell is a respiratory structure adapted for the optimal transmission of respiratory gases to and from the embryo according to its physiological requirements. Therefore amniotes with higher oxygen requirements, such as those that sustain higher metabolic rates, can be expected to have eggshells that can maintain a greater gas flux to and from the egg. Here we show a highly significant relationship between metabolic rates and eggshell porosity in extant amniotes that predicts highly endothermic metabolic rates in dinosaurs. This study finds the eggshell porosity of extant endotherms to be significantly higher than that of extant ectotherms. Dinosaur eggshells are commonly preserved in the fossil record, and porosity may be readily identified and measured. This provides a simple tool to identify metabolic rates in extinct egg-laying tetrapods whose eggs possessed a mineralized shell.
Eggsitentially eggsiting!!! (How many egg puns can you stand!?)
Considerations on the substitution of a type species in the case of the sauropod dinosaur Diplodocus Emanuel Tschopp and Octávio Mateus
The ICZN accepts a morphologically undiagnosable type species for a genus, as long as the type species clearly belongs to the genus in question. This is the case in the sauropod dinosaur Diplodocus. Whereas the Code might make sense in poorly known genera, a substitution of the type species is preferable in the case of Diplodocus. Diplodocus is currently specified by D. longus. Only two caudal vertebrae and a chevron of its holotype remain reasonably complete. These can be referred to Diplodocus as generally perceived, but cannot be distinguished from other Diplodocus species based on autapomorphies. Thus, Diplodocus is specified by a nomen dubium. Diplodocus carnegii is known by the entire skeleton but the skull and the lower foreleg. Casts of its holotype are available in numerous museums around the world, and the species is generally used as reference for studies including Diplodocus. Therefore, it would make little sense to retain the fragmentary species D. longus as the type. In order to maintain Diplodocus with the generally accepted content, and provide taxonomic stability of the higher-level clades for which it is a specifier, it is preferable to substitute the current type species D. longus by D. carnegii.
Makes sense to me, I say go for it.
A new giant species of thresher shark from the Miocene of the United States
Malta David J. Ward and Bretton Kent
In the late Early and Middle Miocene there was burst of gigantism in a number of unrelated species of shark. This event corresponded with the warmest interval of the Neogene, the so-called ‘middle Miocene climatic optimum’, giving high oceanic productivity. In 1942, Leriche described a large species of thresher shark from the Neogene of the USA which he named Alopecias (= Alopias) grandis. The holotype was from the Miocene Calvert Formation of Nomini Cliffs, Virginia. The other was reworked from the Neogene of the Charleston area. This species is poorly known and has received little attention in the subsequent literature. An undescribed species, of similar size but with a serrated cutting edge, is present in slightly younger beds in the Calvert Formation of Calvert Cliffs, Maryland. Both species are present in the Miocene of Malta. The new serrated species has now been described and is currently in press. It is unlikely that the new giant thresher shark possessed an elongated dorsal tail lobe seen in the Recent species. As the dentition is converging on that of a great white shark and its size was similar, it is reasonable to suppose that the body outline was also similar.
*Jaws music* Shame it probably didn’t have the giant tail.