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Re: Pliosaur feeding biomechanics and other non-dino papers
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- Subject: Re: Pliosaur feeding biomechanics and other non-dino papers
- From: Ben Creisler <email@example.com>
- Date: Sat, 14 Jun 2014 15:29:50 -0700
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The new pliosaur feeding paper pdf is available here:
On Sat, Jun 14, 2014 at 2:18 PM, Ben Creisler <email@example.com> wrote:
> Ben Creisler
> A number of recent non-dino papers and two papers now with free pdfs:
> Davide Foffa, Andrew R. Cuff, Judyth Sassoon, Emily J. Rayfield, Mark
> N. Mavrogordato and Michael J. Benton (2014)
> Functional anatomy and feeding biomechanics of a giant Upper Jurassic
> pliosaur (Reptilia: Sauropterygia) from Weymouth Bay, Dorset, UK.
> Journal of Anatomy (advance online publication)
> DOI: 10.1111/joa.12200
> Pliosaurs were among the largest predators in Mesozoic seas, and yet
> their functional anatomy and feeding biomechanics are poorly
> understood. A new, well-preserved pliosaur from the Kimmeridgian of
> Weymouth Bay (UK) revealed cranial adaptations related to feeding.
> Digital modelling of computed tomography scans allowed reconstruction
> of missing, distorted regions of the skull and of the adductor
> musculature, which indicated high bite forces. Size-corrected beam
> theory modelling showed that the snout was poorly optimised against
> bending and torsional stresses compared with other aquatic and
> terrestrial predators, suggesting that pliosaurs did not twist or
> shake their prey during feeding and that seizing was better performed
> with post-symphyseal bites. Finite element analysis identified
> biting-induced stress patterns in both the rostrum and lower jaws,
> highlighting weak areas in the rostral maxillary-premaxillary contact
> and the caudal mandibular symphysis. A comparatively weak skull
> coupled with musculature that was able to produce high forces, is
> explained as a trade-off between agility, hydrodynamics and strength.
> In the Kimmeridgian ecosystem, we conclude that Late Jurassic
> pliosaurs were generalist predators at the top of the food chain, able
> to prey on reptiles and fishes up to half their own length.
> A. O. Averianov & E. V. Popov (2014)
> A pterosaurian vertebra from the Upper Cretaceous of the Saratov Region.
> Paleontological Journal 48(3): 326-329
> DOI: 10.1134/S0031030114030034
> A dorsal vertebra referred to as Azhdarchidae indet. from the Rybushka
> Formation (Upper Cretaceous, Lower Campanian) of the Beloe Ozero
> locality in the Saratov Region is described. Its vertebral centrum has
> a hypapophysis and, at the base of the neural arch, there is a large
> pneumatic foramen. The vertebra possibly belongs to Volgadraco
> bogolubovi Averianov, Arkhangelskii et Pervushov, 2008, described from
> the Rybushka Formation of the Shirokii Karamysh 2 locality in the
> Saratov Region.
> Henri Cappetta, Nathalie Bardet, Xabier Pereda Suberbiola, Sylvain
> Adnet, Driss Akkrim, Mohamed Amalik & Aziza Benabdallah (2014)
> Marine vertebrate faunas from the Maastrichtian phosphates of
> Benguérir (Ganntour Basin, Morocco): Biostratigraphy,
> palaeobiogeography and palaeoecology.
> Palaeogeography, Palaeoclimatology, Palaeoecology 409: 217–238
> DOI: 10.1016/j.palaeo.2014.04.020
> This work is a comprehensive study in relation to the Maastrichtian of
> Selachians and reptiles show the same trends of diversity from L6 up to L2.
> A lower and upper Maastrichtian association is highlighted.
> A possible environmental signal affecting the predator community is noted.
> The associations of Benguérir appear typical of the southern margin of
> the Tethys.
> The Maastrichtian of Benguérir (eastern part of the Ganntour Basin,
> Morocco) consists of about 20 m of phosphates displaying an alternance
> of soft phosphate levels, marly horizons and hard phosphatic
> limestones. Isolated teeth of selachians, actinopterygians and marine
> reptiles are extremely numerous in these phosphatic deposits and have
> been used for biostratigraphical, palaeodiversity and palaeoecological
> Detailed field work allowed to establish an exhaustive list of the
> Benguérir marine vertebrate faunas with their biostratigraphical
> distribution through five main fossiliferous levels (L6 to L2)
> spanning all the Maastrichtian. Their importance for biochronological
> purposes and correlations with other Maastrichtian phosphate deposits
> worldwide appears noteworthy.
> The selachians are currently represented by 60 species belonging to 32
> genera and 7 orders. Among them, the genus Squalicorax is one of the
> most interesting concerning high-resolution biostratigraphy and
> correlations with other phosphate basins because of important rates of
> change noted between the 5 species recovered from base (e.g.
> occurrence of S. africanus) to top (e.g. strong representation of S.
> pristodontus) of the Maastrichtian. The marine reptiles include mainly
> mosasaurids but also scarcer plesiosaurs, chelonians and
> crocodyliforms, representing at least 14 taxa. The mosasaurid
> squamates are the most abundant and diversified with at least 8
> species ranging all along the succession. The actinopterygians include
> mainly teleosts but also pycnodonts, also common in all levels and
> representing at least 7 taxa.
> Selachians and reptiles show the same trends, in terms of species
> richness per level, even if the reptiles are less informative due to a
> less diversified assemblage. For sharks, L6 and L2 show a high
> percentage of genera and species occurring only in the layer
> concerned. The evolution of diversity in actinopterygian fishes is
> less clear because of their low diversity. The use of dissimilarity
> indices and agglomerative method underscores two distinct
> associations: a lower one including the levels L6 and L5, and an upper
> one comprising the levels L4 to L2. These two associations allow to
> separate a lower and an upper Maastrichtian level and are important
> for correlations all around the southern and eastern margins of the
> Tethys. Another clear faunal turnover occurs between L3 and L2,
> because of a high appearance rate in L2 (at least in sharks)
> suggesting an increase in prey abundance, as testified by the rapid
> increase of marine predator density.
> Indeed, and through L6 to L2, a possible signal of an environmental
> damage affecting the predator community can be noted by faunal
> turnovers, even if no significant change in prey association was
> clearly detected.
> From a palaeobiogeographical point of view, the faunal associations of
> Benguérir appear typical of the southern and eastern margins of the
> Tethys, with several typical species not occurring in the northern
> Papers already posted on the DML but now available as free pdfs:
> Mark T. Young, Lorna Steel, Martin P. Rigby, Eliza A. Howlett & Sylvia
> Humphrey (2014)
> Largest known specimen of the genus Dakosaurus (Metriorhynchidae:
> Geosaurini) from the Kimmeridge Clay Formation (Late Jurassic) of
> England, and an overview of Dakosaurus specimens discovered from this
> formation (including reworked specimens from the Woburn Sands
> Historical Biology (advance online publication)
> Open access link:
> Qiyue Zhang, Wen Wen, Shixue Hu, Michael J. Benton, Changyong Zhou,
> Tao Xie, Tao Lü, Jinyuan Huang, Brian Choo, Zhong-Qiang Chen, Jun Liu
> & Qican Zhang (2014)
> Nothosaur foraging tracks from the Middle Triassic of southwestern China.
> Nature Communications 5, Article number: 3973
> Free pdf: