Haikouichthys ercaicunensis (Top 4)
Without a doubt the walking cactus (Diania) and the strange creature with 5 eyes (Opabinia) are strange creatures to talk to, or at least make an interesting conversation; however, you may never wonder which was the most important Cambrian creature, or which belonged to a group important to humans.
Is it really our ancestor?
The answer is no; we did have a common ancestor, but it was not this chordate, in fact, it is impossible to say that one species is descended from another. A hen cannot be a descendant of a Tyrannosaurus, in the same way that a subject with the surname Herrera cannot descend from a surname Simpson, although there are documentaries such as BBC’s “Walking with a Monster”, where Haikouichthys was presented as the ancestor of absolutely all vertebrates, but the truth is that it was only a chordate, exactly as Homo sapiens (human), Canis lupus familiaris (dog) or Columba livia (pigeon) are today.
Why then is Haikouichthys important?
Haikouichthys was undoubtedly a great evolutionary step for vertebrate animals, as they had a well-marked skull, which shows that skulled fish already existed 530 million years ago. The position of the oldest known vertebrate is debated, with the also exceptional “Myllokunmingia fengjiaoa”.
It had cartilaginous skeletal structures, lateral fins, and a single dorsal fin. It is speculated that it might also have a complex brain and could be a founder of the ultimate neural crest. Haikouichthys shares many similarities with the aforementioned creature: “Myllokunmingia fengjiaoa”.
— Palaeos Paleozoic: Cambrian: The Cambrian Period — 2. (2009, 29 abril). WayBackMachine. https://web.archive.org/web/20090429021119/http://www.palaeos.com/Paleozoic/Cambrian/Cambrian.2.html
— Parker, S. (2016). Evolución Toda la Historia (1.a ed.). BLUME.
— Shu, DG., Luo, HL., Conway Morris, S. et al. Lower Cambrian vertebrates from south China.Nature 402, 42–46 (1999). https://doi.org/10.1038/46965
— Shu, DG., Morris, S., Han, J. et al. Head and backbone of the Early Cambrian vertebrate Haikouichthys. Nature 421, 526–529 (2003). https://doi.org/10.1038/nature01264
References of picture 1 and 2, present in figure 2 and 3
— (Picture 1). Martínez, L. (2014, 9 april). Haikouichthys ercaicunensis reconstruction [Illustration]. Wikimedia Commons. https://commons.wikimedia.org/wiki/File:Haikouichthys.jpg
— (Picture 2). Phylogenetic tree of mammals. (2011). [Illustration]. NAUKAS. https://francis.naukas.com/2011/10/28/se-publica-en-science-el-nuevo-arbol-filogenetico-de-los-mamiferos/
Explanatory note: All the images on this blog were made by the author with the canva application.