A new large pantherine and a sabre-toothed cat (Mammalia, Carnivora, Felidae) from the late Miocene hominoid-bearing Khorat sand pits, Nakhon Ratchasima Province, northeastern Thailand.

We describe two large predators from the hominoid-bearing Khorat sand pits, Nakhon Ratchasima Province, northeastern Thailand: a new genus of pantherine, Pachypanthera n. gen., represented by partial mandible and maxilla and an indeterminate sabre-toothed cat, represented by a fragment of upper canine. The morphological characters of Pachypanthera n. gen., notably the large and powerful canine, the great robustness of the mandibular body, the very deep fossa for the m. masseter, the zigzag HSB enamel pattern, indicate bone-cracking capacities. The genus is unique among Felidae as it has one of the most powerful and robust mandibles ever found. Moreover, it may be the oldest known pantherine, as other Asian pantherines are dated back to the early Pliocene. The taxa we report here are the only carnivorans known from the late Miocene of Thailand. Although the material is rather scarce, it brings new insights to the evolutionary history of Neogene mammals of Southeast Asia, in a geographic place which is partly "terra incognita."

Micro-computed tomographic and SEM study of porous bioceramics using an adaptive method based on the mathematical morphological operations.

Numerous clinical studies have demonstrated the influence of the size, number and shape of pores into calcium phosphate ceramics on the process of bone regeneration. The main objective of this study is to determine the microstructure, the morphological characteristics and classes of pores of the prepared hydroxyapatite bioceramic using an adaptive method based on the mathematical morphological operations. The study was carried out using X-ray microtomography and Scanning Electron Microscopy images. The conventional method of openings alone presents limitation of calculation and not sufficient to achieve our objective. The proposed method allowed us to extract local characteristics and calculate precisely the morphological parameters while preserving the original volume of pores. The number and classes of pores with their size, surface of contact of the component and the number of connected pores to each pore were calculated. The method is subjectively and quantitatively evaluated using different computed phantoms and its efficiency is clearly demonstrated through the different reports and measurements generated. The proposed method can have interesting applications in the characterization of porous materials used in the medical field or in other sectors.

A crystallographic study of crystalline casts and pseudomorphs from the 3.5†Ga Dresser Formation, Pilbara Craton (Australia).

Crystallography has a long history of providing knowledge and methods for applications in other disciplines. The identification of minerals using X-ray diffraction is one of the most important contributions of crystallography to earth sciences. However, when the crystal itself has been dissolved, replaced or deeply modified during the geological history of the rocks, diffraction information is not available. Instead, the morphology of the crystal cast provides the only crystallographic information on the original mineral phase and the environment of crystal growth. This article reports an investigation of crystal pseudomorphs and crystal casts found in a carbonate-chert facies from the 3.48 Ga-old Dresser Formation (Pilbara Craton, Australia), considered to host some of the oldest remnants of life. A combination of X-ray microtomography, energy-dispersive X-ray spectroscopy and crystallographic methods has been used to reveal the original phases of these Archean pseudomorphs. It is found with a high degree of confidence that the original crystals forming in Archean times were hollow aragonite, the high-temperature polymorphs of calcium carbonate, rather than other possible alternatives such as gypsum (CaSO4·2H20) and nahcolite (NaHCO3). The methodology used is described in detail.