Could a tail trace be helpful in research on the past? A research team, including scientists from the Polish Geological Institute, the University of Warsaw and the University of Wrocław, has published an article in the journal Biology Letters on the finding of a trace of a diadectid's tail covered in scales. According to the Science in Poland website, the discovery implies the scales, which helped the animals emerge and conquer land, evolved earlier than thought. We asked Prof. Szymon Konwerski, head of the Natural History Collections at the AMU Faculty of Biology, for a commentary on the discovery, emphasising how crucial trace fossils are in research:
- "Exploring the history of life on our planet presents significant challenges for scientists. Among the most demanding is to deal with the fragmented fossil record. Fossils - the 'hard evidence of evolution' - mostly deliver only a fraction of the information needed to reconstruct extinct forms," recalls the scientist. "For vertebrates, it is the skeletons which fossilise, and these are the primary source of knowledge about the majority of taxa," he says. "Such organismal remains are referred to as structural fossils. - An article published in Biology Letters on the structures covering the skin of Palaeozoic amphibians - lepospondyls, and diadectomorphs - animals with transitional features between amphibians and reptiles - makes us realise, that ichnofossils (trace fossils), i.e. all traces left by organisms that once lived - both tracks and, in this case, skin impressions - are also exceptionally valuable in reconstructing the past," emphasises Prof. Szymon Konwerski. - Thanks to such discoveries, we can determine relatively accurately when structures appeared in the skin of quadrupeds that allow them to become independent of the water environment by limiting water loss. It is worth noting that structural fossils cannot usually be accurately related to trace fossils, so systematics with separate taxonomic categories - ichnosaurs and ichnospecies - is applied to the latter. A biologist studying modern animals will find most of the information necessary to classify them in their external structure. The palaeobiologist, of necessity, is most often limited to skeletal structures. The possibility of studying the surface structure of the skin of an extinct animal is an opportunity offered very rarely!" - points out the AMU scientist.
Article in Biology Letters: https://royalsocietypublishing.org/doi/10.1098/rsbl.2024.0041
Photo by Martyna Płaczek
