Mismatch between growth of body and digestive system bends the body, study suggests

Snake embryos coil, but how and why they corkscrew remains unexplored. Weber et al. find that the embryos wind up clockwise via buckling of the rapidly elongating axial body against the slow-growing, ...

Snakes are highly modified lizards, with more than 4,000 living species today. The origin of snakes has long been one of evolutionary biology's most debated questions.

Snake origins were more dynamic than expected. An exceptionally preserved fossil from Brazil shows that the first snakes tried out several different habitats early in their evolution. Researchers at the University of Helsinki led the 3D rendering of the fossil and the comparative analysis of its brain anatomy.

A well-preserved fossil snake from the Late Cretaceous of Brazil shows early ecological and brain shape disparity in the group.

A well-preserved fossil snake from the Late Cretaceous of Brazil shows early ecological and brain shape disparity in the group.

A well-preserved fossil snake from the Late Cretaceous of Brazil shows early ecological and brain shape disparity in the group.

A well-preserved fossil snake from the Late Cretaceous of Brazil shows early ecological and brain shape disparity in the group.

Micro-CT scanning and digital reconstruction of T. mirim The holotype MPM 420 of T. mirim was scanned in the Laboratório de Caracterização Tecnológica of the Escola Politécnica at the University of São Paulo using a Zeiss Xradia Versa XRM-510 Scanner. The specimen was scanned in three parts: one for the skull and anteriormost cervicals, the second one focusing on posterior cervical vertebrae, and the third one on dorsal vertebrae. Parameters were as follows for all scans: 110 kV, 10 W, 25-s exposure (skull and cervicals) or 8 s (dorsals), and a 0.4× objective with HE6 filter resulting in 1,301 images. Voxel sizes were as follows: skull = 17.19 µm, cervicals = 16.2 µm and dorsals = 34 µm. Reconstruction was made with the software Xradia. Reconstruction and the parameters included a beam hardening of 0.08 and a smooth filter with a 0.5 kernel size. Segmentations of osteological structures, cranial endocasts and inner ear were performed using VGSTUDIO MAX v3.5., and 3D cinematic renderings were produced using the SmARTR pipeline36. Morphological and molecular phylogenetic data Here we used the last iteration41 of the total evidence dataset originally published by Simões et al.5, to assess the placement of Tametara not only among...

A well-preserved fossil snake from the Late Cretaceous of Brazil shows early ecological and brain shape disparity in the group.

A well-preserved fossil snake from the Late Cretaceous of Brazil shows early ecological and brain shape disparity in the group.

A well-preserved fossil snake from the Late Cretaceous of Brazil shows early ecological and brain shape disparity in the group.

A well-preserved fossil snake from the Late Cretaceous of Brazil shows early ecological and brain shape disparity in the group.

A well-preserved fossil snake from the Late Cretaceous of Brazil shows early ecological and brain shape disparity in the group.

A well-preserved fossil snake from the Late Cretaceous of Brazil shows early ecological and brain shape disparity in the group.

A well-preserved fossil snake from the Late Cretaceous of Brazil shows early ecological and brain shape disparity in the group.

A well-preserved fossil snake from the Late Cretaceous of Brazil shows early ecological and brain shape disparity in the group.

YouTube video by Di-Poï Evo-Devo LAB Helsinki

A well-preserved fossil snake from the Late Cretaceous of Brazil shows early ecological and brain shape disparity in the group.