Fossil Soft Tissue Reconstructed

Scientists have reconstructed the neck and abdominal muscles of rare, well-preserved 380 million-year-old early jawed fish (placoderm) fossils from the Gogo Formation of northwestern Australia using high-contrast x-ray beams to image the soft-tissue impressions without damage to the fossil.

Chemistry of Bird Ancestor

Using the bright x-ray beam of the Stanford Synchrotron Radiation Lightsource, a team of scientists have decoded portions of the original chemistry of the fossilized Archaeopteryx, revealing similar chemical compositions between this feathered dinosaur and modern birds and thereby strengthening their evolutionary link.

Giant Prehistoric Filter Feeders

New fossil evidence has revealed that the prehistoric seas were filled with giant plankton-eating bony fishes throughout the Jurassic and Cretaceous periods, and all disappeared with the same event that killed the dinosaurs.

Oldest Fossilized Brain Discovered in Kansas

Scientists at the American Museum of Natural History have discovered a 300-million-year-old fossilized brain in the fossils of a fish found in Kansas.

Paleontologists sent the fossil of an iniopterygian, an extinct species related to modern ratfishes or ghost sharks, to the European Synchrotron Radiation Facility for scanning of its interior. Using a technique known as x-ray holotomography, what the scans revealed was a fossilized brain intact within the braincase of the fish as well as parts of the cerebellum, spinal cord and optic lobes, making it the oldest vertebrate brain ever discovered.

Unlike bones, soft tissue is rarely found in fossil records but examples do exist. Further analysis revealed that the brain contains a high level of calcium phosphate whereas the surrounding matrix contains calcium carbonate. Researchers theorize that bacteria covered the brain before it could decay and induced its chemical phosphatization, preserving its structure.

These results were published in the March 2nd edition of the Proceedings of the National Academy of Science.

Source: ScienceDaily

Fish Fossils Reveal Internal Sexual Reproduction

Scientists at Museum Victoria in Melbourne and the Natural History Museum in London have discovered internal sexual reproduction in early fish fossils, some 30 million years earlier than previously believed.

Fossils of the 380 million-year-old fish Incisoscutum richiei, or armored placoderm fish, revealed females carrying fossilized embryos. This provides the earliest evidence for internal sexual reproduction and internal incubation of offspring that included bearing live young. Subsequent analysis of the male of the species also uncovered a previously overlooked pelvic fin not present on the female, supposedly used to grip the female during reproduction.

Researchers expected prehistoric fish to have a much more simple reproductive strategy, similar to the external fertilization of today's fish species where sperm and egg combine in the water and embryos develop outside the body. The fossilized fish and embryos are from the Gogo dig site in Western Australia and are the oldest known evidence of a vertebrate mother.

These results were published in the February 26th edition of Nature.

Source: Yahoo!