Evolution

Reconstruction of Hallucigenia sparsa

Hallucigenia, an animal lived in the Cambrian period, between 520 and 505 million years ago, has been considered for decades a really weird animal, hence the name. It looked like it could be part of a family that got extinct but the discovery of new fossils allowed to study it better since the ’90s. Now according to a new research carried out at the University of Cambridge hallucigenia, or rather the hallucigenia genus, is a lobopode, related to modern velvet worms, part of the Onychophora phylum.

Artistic concept of Metaspriggina swimming near colonies of the cyanobacterium Marpolia

The discovery of new fossils of Metaspriggina walcotti allowed to shed light on the origin of some of the characteristics of the chordates, animals with a backbone structure which in vertebrates has become the spine. It’s an animal lived about 500 million years ago, during the Middle Cambrian period. Due to their worm-like appearance and a length that could reach 10 centimeters (almost 4 inches), they don’t seem like much but they could be the ancestors of all vertebrates living today.

Specimen of Pikaia exposed at at the Smithsonian in Washington

The Burgess Shale is an area in Canada very well known in the world of paleontology because it represents an extraordinary reservoir of fossils from the Middle Cambrian, which is about five hundred million years ago. In 2012, in Kootenay National Park, about 40 km from the original site, a new deposit of fossils was discovered described in a paper just published in the journal “Nature Communications”.

Fossil of Tiktaalik in the Field Museum, Chicago

A team of paleontologists led by Professor Neil Shubin from the University of Chicago published in the journal “Proceedings of the National Academy of Sciences” the results of a research on Tiktaalik roseae. It’s a species that lived during the Devonian period, about 375 million years ago, which is a transitional form between fish and legged animals. This research highlights the adaptation of the hind fins of this animal, showing that it had already started in fish.

Flowers of Amborella trichopoda

The sequencing of the genome of the amborella trichopoda (photo ┬ęScott Zona) helped solve the mystery of the appearance of flowering plants during the Cretaceous. Charles Darwin called it an abominable mystery due to the difficulty of understanding how plants evolved to result in the birth of the flowers. The Amborella Genome Project, which also published online the DNA sequences of this plant, has uncovered a horizontal gene transfer from other organisms.