Thread by @singerstone

I am very happy to share our last paper on #proboscidean #macroevolution, a fruitful collaboration between paleontologists from Spain, Finland, UK and Argentina. The main conclusions in this thread (1/n)

nature.com/articles/s4155…

Elephants are almost mystic animals, and the idyllic sight of these giants in the wild may suggest that places like this one in Samburu have been unchanged for millions of years. (2/n)

Photograph by Michael Nichols / National Geographic Society

But elephants are in fact the last relics of a lineage that just 3 Ma had more than 30 species inhabiting Africa, Europe, Asia, and the Americas. More than 180 species have been described in the fossil record!!! (3/n)

Using information of 17 ecomorphological traits [dental and cranio-mandibular aspects, mastication mode, tusks, body mass, locomotion] for all these species, we identify 8 large proboscidean functional types (PFTs). (4/n)

The reconstructions of each PFT by @OSanisidro help to get an idea of the huge disparity of forms and ecologies that this mammalian order attained in he past. (5/n)

For 30 Myr, proboscideans were restricted to Afro-Arabia, and only two PFTs evolve in all that time. The dispersal of the group outside Afro-Arabia ~23Ma and the new settings in terrestrial ecosystems brought by the Neogene changed everything. (6/n)

Lineages outside Afro-Arabia evolved 25 times faster, and several PFT emerged in a few Myr. (7/n)

PTFs over time 👇🏼

Higher ecological disparity reduced competition, and landscapes with two or more species of proboscideans became the norm (8/n)

For example, 4 Ma in Turkana, Kenya, australopithecines shared the landscape with up to 4 different species of proboscideans (Anancus ultimus, Deinotherium bozasi, Loxodonta adaurora and Loxodonta exoptata). Artwork by Julius Csotonyi (csotonyi.com) (9/n)

The Late Miocene marks a turning point. We looked at extinction rates, and in the last 10 Myr, these rates correlate with temperature trends and also temperature fluctuations severity (10/n)

3 and 2.4 Ma extinction quintupled in Eurasia en Africa respectively, likely stemming from the onset of glacial-pulse dynamics. This was the end for emblematic beasts like the deinotheres (11/n)

[artwork by Zdeněk Burian]

Extinction further skyrocketed starting 160 and 75 Kya until the present. But this last pulse is not detected in Africa, suggesting that the last annihilation regime was triggered by further Holarctic climate disturbances (12/n)

Wait!! Our results are still compatible with human activities contributing to the decline of proboscideans towards the end of the Pleistocene (13/n)

Thanks to all the authors!!

@cantalab @OSanisidro, S Zhang, MT Alberdi, JL Prado @FernandoBlancoS, and J Saarinen

Please retweet and spread the word. The world is full of proboscidean lovers!! 🕺🏻👯🐘👯🕺🏻

Oh! and macroevolution lovers too!! 🤓📈📉