Little skate - Leucoraja erinacea (Photo Andy Martinez/NOAA)

An article published in the journal “Cell” describes a research on the origin of the types of neurons needed to coordinate walking on the mainland. A team of researchers from the New York University School of Medicine focused in particular on the species little skate (Leucoraja erinacea), part of the most primitive vertebrate group, studying its neuromuscular and genetic development. The conclusion is that some fish started walking on the sea floor about 420 million years ago, about 20 million years before the early tetrapods started colonizing the mainland.

Artist's concept of Carboniferous rainforest (Image courtesy Mark Ryan. All rights reserved)

An article published in the journal “Proceedings of the Royal Society B” describes a research on the changes that occurred during the Carboniferous rainforest collapse. According to a team of scientists led by the British University of Birmingham, a climate change that occurred about 307 million years ago caused a drought that led to the extinction of some groups of tetrapods, the first vertebrates that lived on the mainland, favoring at the same time other groups.

Kootenayscolex barbarensis fossil (Image courtesy Jean-Bernard Caron / Royal Ontario Museum)

An article published in the journal “Current Biology” describes a research on Kootenayscolex barbarensis, a bristle worm (class Polychaeta) that lived about 508 million years ago in the site of today’s Marble Canyon, in the Burgess Shale, Canada. Karma Nanglu and her supervisor Jean-Bernard Caron of the University of Toronto and the Royal Museum of Ontario studied this very ancient annelid. It’s a sea animal although it’s related to the current earthworms. The most important thing is that its discovery provides new information on the origin of the annelids’ head.

Fossil scales of Jurassic Butterflies and Moths (Image courtesy van Eldijk et al.)

An article published in the journal “Science Advances” describes the discovery of the oldest fossil remains of lepidoptera, the order of insects that includes butterflies and moths. A team of scientists analyzed soil samples in which Professor Paul K. Strother of Boston College previously identified fossil remains. The dating at about 200 million years ago indicates that those insects existed tens of millions of years before flowering plants, while many previous estimates suggested a possible coevolution between the two groups.

Habelia optata fossil (Image courtesy Jean-Bernard Caron. Copyright: Royal Ontario Museum)

An article published in the journal “BMC Evolutionary Biology” describes a research on Habelia optata, an arthropod that lived in the mid-Cambrian period, about 505 million years ago. It’s one of the many organisms that lived at that time whose fossils caused perplexities in paleontologists with difficulty in their classification. Now Cédric Aria of the University of Toronto and Bernard Caron of the Royal Ontario Museum believe it was related to the ancestors of the current species of the chelicerate subphylum.