New findings are rewriting the evolutionary history of “fish to humans”.

The discovery of a fossil “treasure hoard” sheds light on the rise of fish.

Researchers at the Chinese Academy of Sciences’ Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) have recently found two fossil sites in the early Silurian strata of southwestern Guizhou and Chongqing that are rewriting the evolutionary history “from fish to man.”

Four different articles describing their findings were recently published in the journal Nature.

Humans are one of the 99.8% of species of extant vertebrates that are gnathostomes, or jawed vertebrates. The basic body plan and several key human organs can be traced back to the origin of the gnathostomes. One of the most significant developments in the evolution of vertebrates is the emergence of the jaws.

The Chongqing Fish Fossil Storehouse is the only early Silurian repository in the world that preserves complete fish with jaws from head to tail, offering an unparalleled opportunity to peer into the unfolding ‘dawn of the fish’. Credit: NICE Tech/ScienceApe

How this innovation came about remains a mystery, however, as fossils of early jawed vertebrates were not discovered in large numbers until the beginning of the Devonian (419 million years ago), although molecular data suggest that this should be the origin of jawed vertebrates are more than before Occurred 450 million years ago. As a result, there is a significant gap in the fossil record of early jawed vertebrates that has lasted at least 30 million years from the late Ordovician to the Silurian.

Silurian fish graphic. Credit: NICE Tech/ScienceApe

The latest findings by IVPP’s Zhu Min’s team, unearthed from two new fossil sites, shed light on the rise of jawed vertebrates: these jawed fish thrived in the waters of the South China Block at the end of the Silurian by the time more diverse and larger jawed fish had evolved and began to flourish at least 440 million years ago to spread across the world, opening the Fish Landing saga and eventually evolving our humans.

Discoveries of fish fossils from the two depositories are helping to trace many human body structures back to ancient fish around 440 million years ago, filling in some important gaps in “fish-to-human” evolution and providing further ironclad evidence for the evolutionary path.

The Chongqing fish fossil deposit in the Upper Red Beds of the Silurian system dates back to 436 million years ago. It is the world’s only early Silurian deposit (fossil deposit of exceptional preservation) that preserves complete fish with jaws from head to tail and offers an unparalleled opportunity to glimpse the unfolding ‘dawn of the fish’. This fossil “hoard” sits alongside other major Chinese deposits: Chengjiang Biota and Jehol Biota, all of which provide important puzzles previously missing from the tree of life.

References: “The oldest gnathostomous teeth” by Plamen S. Andreev, Ivan J. Sansom, Qiang Li, Wenjin Zhao, Jianhua Wang, Chun-Chieh Wang, Lijian Peng, Liantao Jia, Tuo Qiao and Min Zhu, September 28, 2022, Nature.
DOI: 10.1038/s41586-022-05166-2

“Galeaspid Anatomy and the Origin of Paired Vertebrate Appendages” by Zhikun Gai, Qiang Li, Humberto G. Ferrón, Joseph N. Keating, Junqing Wang, Philip CJ Donoghue, and Min Zhu, September 28, 2022, Nature.
DOI: 10.1038/s41586-022-04897-6

“Spiny chondrichthyan from the Lower Silurian of South China” by Plamen S. Andreev, Ivan J. Sansom, Qiang Li, Wenjin Zhao, Jianhua Wang, Chun-Chieh Wang, Lijian Peng, Liantao Jia, Tuo Qiao and Min Zhu, 28. September 2022, Nature.
DOI: 10.1038/s41586-022-05233-8

“The Oldest Complete Jaw Vertebrates from the Early Silurian of China” by You-an Zhu, Qiang Li, Jing Lu, Yang Chen, Jianhua Wang, Zhikun Gai, Wenjin Zhao, Guangbiao Wei, Yilun Yu, Per E. Ahlberg, and Min Zhu, September 28, 2022, Nature.
DOI: 10.1038/s41586-022-05136-8

The study was funded by the Chinese Academy of Sciences.