Gabriele Sansalone

Morphological integration and functional modularity in the crocodilian skull.

We explored the morphological organization of the skull within Crocodylidae, analyzing functional and phylogenetic interactions between its 2 constituent functional modules: the rostrum and the postrostrum. We used geometric morphometrics to identify localized shape changes, focusing on the differences between the major clades of the crown-group Crocodylia: Alligatoridae and Crocodylidae. We used published bite performance data to correlate rostral function with postrostral morphology. The skull modules appear more integrated within Alligatoridae than within Crocodyliade. Phylogenetic effects on shape variation are more evident in Alligatoridae than in Crocodylidae, where functional parameters concerning the rostral morphology are proportionally more important than phylogeny. Long-snouted species are characterized by low structural performance, which is significantly associated with a reduction of the pterygoid-quadrate cranial nipper, suggesting that the nipper is important for the ingestion of large food items in generalist species. This functional association is coupled with a significant evolutionary allometry at the clade level, while Alligatoridae and Crocodylidae show different degrees of evolutionary allometry for their entire shape and rostrum. The postrostrum is more conservative than the rostrum in terms of morphospace occupation, evolutionary allometry and phylogenetic signal.

Digging adaptation in insectivorous subterranean eutherians. The enigma of Mesoscalops montanensis unveiled by geometric morphometrics and finite element analysis

The enigmatic Early Miocene fossorial mammal Mesoscalops montanensis shows one of the most modified humeri among terrestrial mammals. It has been suggested, on qualitative considerations, that this species has no extant homologues for humerus kinematics and that, functionally, the closest extant group is represented by Chrysochloridae. We combine here three dimensional geometric morphometrics, finite element analysis and phylogenetic comparative methods to explore the shape and mechanical stress states of Mesoscalops montanensis as well as of extant and extinct Talpidae and Chrysochloridae under realistic digging simulations. Evolutionary convergence analyses reveal that the shape of Mesoscalops montanensis represents a unique morphology in the context of fossorial mammals and that its functional performance, albeit superficially similar to that of extant Chrysochloridae, still represents a nonconvergent optimum for adaptation to digging. J. Morphol. 276:1157–1171, 2015.

New Systematic Insights about Plio-Pleistocene Moles from Poland

The generic attribution of the Plio-Pleistocene Polish moles ?Neurotrichus polonicus and ?Neurotrichus skoczeni has been questioned several times in the past. The fossil material belonging to ?Neurotrichus polonicus and ?Neurotrichus skoczeni is re-evaluated here and a new diagnosis is provided on the basis of qualitative considerations. In addition, a Geometric Morphometric analysis of the humerus has been performed including both extant and extinct Neurotrichini and Urotrichini taxa for comparison. Our results proved the unique morphology of the Polish material suggesting a distinct taxonomic state. The morphological variations evidenced by the humeral shape analysis agree with the observed qualitative differences and support a new generic allocation. The new genus Rzebikia gen. nov. is proposed for all the material previoulsly ascribed to ?Neurotrichus polonicus and ?Neurotrichus skoczeni.

Talpa fossilis or Talpa europaea? Using geometric morphometrics and allometric trajectories of humeral moles remains from Hungary to answer a taxonomic debate

The taxonomic validity of Talpa fossilis has been subject to a longstanding debate. Talpa fossilis has been considered as a chronospecies, stratigraphic species, and finally as junior synonym of Talpa europaea. In this study, the large humeral sample of T. fossilis and T. europaea from the Plio-Pleistocene of Hungary is re-investigated using a geometric morphometrics analysis. Furthermore, the differences in the static allometric slopes under the allometric constraint hypothesis were tested. The results indicate that T. fossilis and T. europaea have significant differences in both size and shape. The allometric slopes of T. fossilis and T. europaea were found to be different, revealing that the two taxa follow different patterns of shape modification according to size. In light of this evidence, T. fossilis and T. europaea are supported as two distinct species. Gabriele Sansalone. Universita di Roma Tre, Dipartimento di Scienze, L.S. Murialdo, 1 – 00146 Roma, Italy and Center of evolutionary ecology, Pesche, Italy. gsansalone@uniroma3.it Tassos Kotsakis. Universita di Roma Tre, Dipartimento di Scienze, L.S. Murialdo, 1 – 00146 Roma, Italy and Center of evolutionary ecology, Pesche, Italy. kotsakis@uniroma3.it Paolo Piras. Universita di Roma Tre, Dipartimento di Scienze, L.S. Murialdo, 1 – 00146 Roma, Italy and Center of evolutionary ecology, Pesche, Italy and Dipartimento di Scienze Cardiovascolari, Respiratorie, Nefrologiche, Anestesiologiche e Geriatriche, Sapienza-Universita` di Roma, Roma, Italy and Dipartimento di Ingegneria Strutturale e Geotecnica Sapienza, Universita di Roma. paolo.piras@uniroma3.it

Condylura (Mammalia, Talpidae) reloaded: New insights about the fossil representatives of the genus

The star nosed mole, Condylura cristata, due to its morphological and behavioural peculiarities, has been deeply investigated by different authors. By contrast, very little is known about the phylogenetic relationships, evolution and diversity of the fossil members of this genus. In the present study we provide new insights about the fossil specimens ascribed to Condylura taking into account systematic, palaeobiogeographical and palaeoecological aspects. Further, we provide a re-description of a fossil Condylura from the middle Miocene of Kazakhstan. We confirm that the Kazakh fossil belongs to the genus Condylura, based on humeral morphological features, and we discuss its implications and impact on the phylogenetic scenario and ecology of this peculiar talpid genus. This specimen represents the earliest record of the genus, thus suggesting an Eurasiatic origin instead of the most commonly accepted scenario of a North American one. The presence of both plesiomorphic and apomorphic characters in Condylura strongly supports the hypothesis that this genus could be considered as sister clade of Talpinae. Gabriele Sansalone. Roma Tre University of Rome, Dept. of Sciences, L.S. Murialdo, 1 – 00146 Rome, Italy/Center for evolutionary ecology, C.da Fonte Lappone, Pesche, Italy/Form, Evolution and Anatomy Research Laboratory, Zoology, School of Environmental and Rural Sciences, University of New England, Armidale, NSW 2351, Australia gsansalone@uniroma3.it Tassos Kotsakis. Roma Tre University of Rome, Dept. of Sciences, L.S. Murialdo, 1 – 00146 Rome, Italy/ Center for evolutionary ecology, C.da Fonte Lappone, Pesche, Italy kotsakis@uniroma3.it Paolo Piras. Center for evolutionary ecology, C.da Fonte Lappone, Pesche, Italy/Dipartimento di Scienze Cardiovascolari,Respiratorie, Nefrologiche, Anestesiologiche e Geriatriche, “Sapienza” University of Rome, Rome, Italy/Dipartimento di Ingegneria Strutturale e Geotecnica, “Sapienza” University of Rome, Via Eudossiana 18, 00100, Rome, Italy ppiras@uniroma3.it

EVOLUTIONARY TRENDS AND STASIS IN MOLAR MORPHOLOGY OF RHAGAPODEMUS - RHAGAMYS LINEAGE IN THE PLEISTOCENE OF SARDINIA

Stasis, random walk and directional evolutionary patterns have been tested on the lower and upper first molars of the Rhagapodemus - Rhagamys lineage (Rodentia, Muridae) from Middle and Late Pleistocene fissure fillings of Monte Tuttavista, Orosei, Sardinia, Italy. We recorded the maximum length/maximum width ratio and size on 252 lower first molars and 208 upper first molars belonging to different fossil samples of Rhagapodemus minor and Rhagamys orthodon in order to explore evolutionary dynamics underlying molar morphology evolution. Akaike Information Criterion (AICc) was used for selection of the best model of evolution, in order to distinguish different evolutionary patterns. Our results clearly show that Rhagapodemus - Rhagamys lineage undergoes stasis during the middle and late Pleistocene of Sardinia, while size shows a random walk pattern between populations, characterized by an increase in size at the Rhagapodemus minor- Rhagamys orthodon transition.