Preliminary observations on the bone histology of the Middle Triassic pseudosuchian archosaur Batrachotomus kupferzellensis reveal fast growth with laminar fibrolamellar bone tissue

The bone tissue of femur, rib, and gastralia from three different individuals of the Middle Triassic pseudosuchian Batrachotomus kupferzellensis from southern Germany is studied. The femoral bone tissue comprises laminar fibrolamellar bone tissue throughout and is stratified by three annual growth cycles, indicating that the individual died early in its fourth year of life, at which time it had reached 87% of maximum known femur length. Thus, compared with most other Pseudosuchia (e.g., phytosaurs, aetosaurs, and most crocodylomorphs, including marine taxa), Batrachotomus achieved its large body size in a very short time by fast, although interrupted, growth and not by protracted longevity. Such fast growth as well as the organization of the tissue is similar to the condition observed in ornithodirans. The pseudosuchians Effigia and Postosuchus also show fibrolamellar tissue, but vascular density is lower when compared with Batrachotomus and dominated by a longitudinal organization of primary osteons. The rib and gastralium of Batrachotomus both show an inner spongious organization surrounded by a ring of compact, avascular, highly organized parallel-fibered and/or lamellar bone largely covered by short fibers. Maximal growth cycle count in the proximal rib sample suggests an age of at least 11 years for this individual with a reduction of growth rate after the sixth cycle.SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVPCitation for this article: Klein, N., C. Foth, and R. R. Schoch. 2017. Preliminary observations on the bone histology of the Middle Triassic pseudosuchian archosaur Batrachotomus kupferzellensis reveal fast growth with laminar fibrolamellar bone tissue

Enhancement of the Curie temperature in GaMnAs/InGaMnAs superlattices

We report on an enhancement of the Curie temperature in GaMnAs/InGaMnAs superlattices grown by low-temperature molecular beam epitaxy, which is due to thin InGaMnAs or InGaAs films embedded into the GaMnAs layers. The pronounced increase of the Curie temperature is strongly correlated to the In concentration in the embedded layers. Curie temperatures up to 110 K are observed in such structures compared to 60 K in GaMnAs single layers grown under the same conditions. A further increase in T$_C$ up to 130 K can be achieved using post-growth annealing at temperatures near the growth temperature. Pronounced thickness fringes in the high resolution X-ray diffraction spectra indicate good crystalline quality and sharp interfaces in the structures.Comment: 4 pages, 4 figures, submitted to Appl. Phys. Let

Upper Paleozoic to Lower Mesozoic Tetrapod Ichnology Revisited : Photogrammetry and Relative Depth Pattern Inferences on Functional Prevalence of Autopodia

In recent years photogrammetry has become an essential tool in the study of tetrapod footprints. Morphological analyses of footprints are interpretative; thus, researchers should use as much information as possible in order to eventually provide an objective conclusion. In this regard, photogrammetry is an extremely helpful tool to avoid potential biases and to better present ichnological data. We review the use of this technique in several Permian and Triassic tetrapod ichnological studies, with considerations on (1) ichnotaxonomy, (2) track-trackmaker correlation, (3) locomotion and/or behavior, (4) substrate induced effects, and (5) preservation of the fossil record and heritage. Furthermore, based on the available three-dimensional (3D) data on Permian and Triassic material, we present a first qualitative interpretation of relative depth patterns and the related functional prevalence (most deeply impressed area) within footprints. We identified three main groups: (1) anamniote, captorhinomorph/parareptile tracks (medial-median functional prevalence), (2) diapsid tracks (median functional prevalence), and (3) synapsid tracks (median-lateral functional prevalence). The use of 3D photogrammetric models brings new light to the tetrapod footprint record, helping to better understand tetrapod communities throughout the late Paleozoic (and the end-Guadalupian and end-Permian extinctions) and the tetrapod recovery during the early Mesozoic

Electronic and magnetic properties of GaMnAs: Annealing effects

The effect of short-time and long-time annealing at 250C on the conductivity, hole density, and Curie temperature of GaMnAs single layers and GaMnAs/InGaMnAs heterostructures is studied by in-situ conductivity measurements as well as Raman and SQUID measurements before and after annealing. Whereas the conductivity monotonously increases with increasing annealing time, the hole density and the Curie temperature show a saturation after annealing for 30 minutes. The incorporation of thin InGaMnAs layers drastically enhances the Curie temperature of the GaMnAs layers.Comment: 4 pages, 6 figures, submitted to Physica

Cranial shape evolution of extant and fossil crocodile newts and its relation to reproduction and ecology

The diversity of the vertebrate cranial shape of phylogenetically related taxa allows conclusions on ecology and life history. As pleurodeline newts (the genera Echinotriton, Pleurodeles and Tylototriton) have polymorphic reproductive modes, they are highly suitable for following cranial shape evolution in relation to reproduction and environment. We investigated interspecific differences externally and differences in the cranial shape of pleurodeline newts via two-dimensional geometric morphometrics. Our analyses also included the closely related but extinct genus Chelotriton to better follow the evolutionary history of cranial shape. Pleurodeles was morphologically distinct in relation to other phylogenetically basal salamanders. The subgenera within Tylototriton (Tylototriton and Yaotriton) were well separated in morphospace, whereas Echinotriton resembled the subgenus Yaotriton more than Tylototriton. Oviposition site choice correlated with phylogeny and morphology. Only the mating mode, with a random distribution along the phylogenetic tree, separated crocodile newts into two morphologically distinct groups. Extinct Chelotriton likely represented several species and were morphologically and ecologically more similar to Echinotriton and Yaotriton than to Tylototriton subgenera. Our data also provide the first comprehensive morphological support for the molecular phylogeny of pleurodeline newts