Updated November 10, 2020
This post is now 9 years old. About 1500 additional taxa have been added to the large reptile tree, many of which are human ancestors not known to me (and often others) in 2011. Some taxa listed below are now on side branches. Dozens of fish and basal tetrapods were added that precede the listed basal tetrapods.
The Latest List of Human Ancestors
The evolution of humans from australopithecines and beyond has been well chronicled. We know the beginning and we know the end. That list of what happened in between keeps growing as more transitional taxa are added to fill in the present gaps, which keep getting smaller and smaller.
The best represented lineage hasn’t changed much since the publication of From The Beginning, a book I wrote that was published by Little Brown in 1991. At the time it was a first of its kind. FTB illustrated 36 steps in the evolution of humans: from raw chemicals, through bacteria, worms, fish, and the rest of our clade. Every turn of the page introduced the reader to a new taxon that added, modified and/or subtracted various body parts, abilities and behaviors. That list of 36 has held up pretty well in the last twenty years, with only a few exceptions. Now Ophiacodon and Nikkasaurus would replace Haptodus. Tree shrews would be dropped in favor of a primitive carnivore, Vulpavus.
Bush or Ladder?
As in From the Beginning, this blog and reptileevolution.com seek to provide the latest insight into the origin and evolution of various animals (including humans). Everyone knows the process of evolution produces a branching bush, but if you want to focus on just one lineage, to see how your own body parts were modified by evolution over time and generations, it’s an unbroken ladder. By that I mean, every one of our ancestors, in an unbroken chain, successfully grew to maturity, mated and reproduced. They weren’t eaten, killed while hatching or destroyed by an asteroid impact. Our ancestors always found safe haven. Some of their offspring were a little taller, a little shorter, a little more aggressive, a little less able to breathe with gills, etc. They evolved a little bit at a time. Over time all those little bits added up.
Of the millions of ancestors we all share in common, here’s an abbreviated and clickable list that will provide more information about each step in the process of human evolution going back to the first of our ancestors to walk on land. It’s like the book From the Beginning, only its on the web.
11. Elliotsmithia 11a. Apsisaurus 12. Archaeothyris. 13. Ophiacodon 14. Nikkasaurus. 15. Biarmosuchus. 16. Stenocybus. 17. Eotitanosuchus and Scymnognathus. 18. Aelurognathus. 19. Procynosuchus. 20. Thrinaxodon. 21. Chiniquodon. 22. Pachygenelus.
Evidence and support in the form of nexus, pdf and jpeg files will be sent to all who request additional data.
No references this time.
>> Returning visitors will note a small edit based on updated data at positions 10 and 11.