Florentino Ameghino and the Argentinian Origins of Humanity

An early 1900’s Argentinian paleontologist was certain all humanity traced its origins to the “Land of Giants.”

Cover image credit: Ameghino (Public Domain) and a skull of one of his “proto humans.” (Aleš Hrdlička)1

In the early months of 1910, German paleontologist Max Friedemann traveled to Argentina. He had heard of an odd find that would completely change how the thinking of the evolution of our species, and he was eager to see the fossil specimens himself. After he arrived in the Museo Nacional de Buenos Aires he was greeted by an exited and eccentric man who rushed him into the museum’s collections.

In the dusty room, the Argentinian museum director opened up a case and showed Friedemann a femur and the top part of a skull, both clearly human in origin. The fossils were discovered in Argentina, and the museum director insisted they came from two fossil hominids that were millions of years old: Tetraprothomo arentinus and Diprothomo paltensis.

The director, Florentiono Ameghino, a middle aged man with a graying beard, described to Friedemann how the remains were some of the many convincing pieces of evidence that all of humanity traced its origins to, of all places, Patagonia.

Friedemann was amazed. The odd finds flew in the face of established doctrine that postulated humans had evolved first in Africa. But that was not the only amazing find Ameghino made. In fact, the Argentinian paleontologist argued, he had more evidence that not only had humans evolved in South America, but all primates were from Patagonia. In fact, all old world primates evolved from human ancestors, not the other way around!2

Friedmann was shocked and took casts back to Berlin to show the European science community. But they would open Ameghino, then a world-renown expert on mammalian paleontology, up to criticism and ridicule.

However, Ameghino’s insistence was impart inspired by the colonial nature of paleontology in South America. He wanted to wrest the control of his country’s paleontological interpretation from the Euro-American establishment. He made numerous strides in paleontology that made him world famous in his day for good reason. Yet ultimately his nationalism blinded him in a tragic way we will explore. First, let’s talk more about Ameghino and his remarkable discoveries. Next time, I’ll dive more into why he got human evolution so wrong.

The Paleontological Giant from Argentina

Apes are men that turned beastly.

Florentino Ameghino, 1906
A sketch of Florentino Ameghino from the 1870’s (Public Domain).

Florentino Ameghino was a child of Genoese immigrants who came to Argentina in the mid 1850’s. He grew up in the town of Luján, Argentina, around 60 km (or nearly 40 miles) northwest of Buenos Aires. This part of Argentina had long been known as a great source of fossils. It was this setting that perfectly suited Ameghnio to a life of paleontological study.2

He started his journey when he became interested in ancient humans who lived in the Pampas region of Argentina. As part of this work, he traveled to the Natural History Museum in Paris to investigate human artefacts and remains stored there. While perusing the museum’s archives, he discovered the immense trove of fossils that had been extracted from Argentina (that I hinted at last post).2

Ameghino rushed back to Argentina and shifted his focus to understanding the mammalian paleontological history of his homeland. He started hunting for fossils with his brother, Carlos, and the two amassed a large collection. From this work, Ameghino combined his two interests of ancient humans and paleontology to investigate ancient human origins in Patagonia.2

Ameghino and his brother set up a fossil hunting business, where Carlos was trained in field work. He would go out into the rough, distant terrain of Patagonia and hunt for the giant bones that were then brought back to the family book store where Florentino would then study, classify, and report on the finds.

Soon Ameghino became famous around Argentina as a professionally trained and world-class paleontologist. People from all over South America sent him fossils for study, including the president of Argentina. However the result was a large, unorganized cache of fossils that were no longer being accounted for and maintained in centralized museum archives. Ameghino’s notoriety made him well off enough financially that he was able to fund many of his own expeditions, which amazed his contemporaries.2

Ameghino developed a close professional relationship with the Germain biologist Hermann von Ihering who was living in Brazil at the time. The two closely worked together on the fossil finds of Patagonia. The Ameghinos and von Ihering established a system where Carlos collected the fossils and observed the geology of the field sites, Florentino classified the fossils and established their place within the geologic time scale, and von Ihering identified different important invertebrate fauna that were used in the geologic age dating.2

The company’s work took off when Ameghino was appointed to a post in the Museo Nacional de Buenos Aires where he hired Carlos as an employee. The appointment opened Ameghino up to the immense collections of the museums, and he in turn used the museums facilities to make numerous casts that he then sent to schools across Argentina and to museums and labs in Europe. The casts made him world famous and put in place a system of selling fossil casts that limited the removal of fossils from Argentina.2

Ameghino’s discoveries shocked the paleontological establishment. However, they also opened him up to intense criticism that ultimately would make him more remembered for his mistakes instead of his successes.

The “Patagonian Controversy”

After each of Carlos Ameghino’s forays into Patagonia, he returned with rare and striking mammal fossils that were unlike any before seen. Florentino Ameghino wrote about the numerous new species and even orders of mammals found in the dry stretches of the Patagonian wilderness. The paleontological establishment was astounded by the creatures Ameghino described in his numerous publications, and soon they were clamoring to visit Argentina and see the rare remains for themselves.

Ameghnio made an even bolder claim in his publications about the finds: all of his fossils were from the Cretaceous Period, more than 70 million years ago. This would make them the oldest known diverse, and advanced, mammal assemblages ever found.

The age of Ameghino’s fossils, although dubious, implied that they were therefore the ancestors of all modern mammal orders, including all marsupials in Australia. All mammals, the Argentinian paleontologist claimed, evolved in Patagonia and had subsequently migrated out of South America, likely through undiscovered land bridges.2

The status quo of paleontology scoffed at his claims. However, their problem with Ameghino was not that there was a diverse mammalian assemblage in South America, nor did they mind that he invoked somewhat fanciful, temporal land bridges linking the continents. They agreed with all of these bold claims.

Instead, they took issue with his ideas that mammals could evolve in South America.

The “standard” hypothesis at the time that evolution was slower in the Southern Hemisphere and thus all life had to evolve in the Northern Hemisphere (conveniently enough in places like Europe). That this was based on their biased collections, which were mainly from the Northern Hemisphere, did not dissuade these narrow-minded arguments. Ameghino and his brother had found evidence that was clearly contrary to this status quo. Mammals had evolved in South America just as they had elsewhere.2

In addition, Ameghino reported on ancient primates related to Old World lemurs and monkeys. Therefore, Ameghino surmised, human’s ancestors likewise evolved in Patagonia and had dispersed to Africa, not the other way around as was commonly believed at the time. He concluded that all mammals had evolved in Patagonia and then had dispersed outwards through various land bridges.

When established paleontologists scoffed at his claims, Ameghino pointed out that the standard assumptions of the paleontological status quo did not fit into the observations he made. There were clearly a panoply of new mammals never before seen elsewhere. The genus Pryortherium, an odd rhinoceros-like mammal with a short trunk, which Ameghiono found in his “Cretaceous-aged” deposits, appeared to be a basal from of all elephants (which modern paleontologists no longer agree with).3,4

Ameghino’s assertion that these basal mammals were Cretaceous in age is completely wrong, and was quickly identified as such by his contemporaries. Most mammals in the Cretaceous were small and not nearly as “advanced” as the forms Ameghino described. He suggested the fossil mammal assemblage was Cretaceous because of vague stratigraphic claims made by his brother on the position of the mammal fossils and their association with dinosaur fossils. Later research showed that this was incorrect.

He also was certain his fossil species were related to forms found in other continents because of their similar, yet more privative forms. Therefore they had to be older, ancestral species of the same lineage. Paleontologists now know that while similar forms do not always signify ancestral relationships. In a process called convergent evolution, distantly related species can evolve similar morphological traits even when they are completely unrelated. Ameghino’s next discovery would only fuel his critics even more.

An odd mammal with a short elephant like snout and jagged teeth
Robert Bruce Horsfall’s 1913 sketch of Pyrotherium (Public Domain)

The South American Origins of Humanity

Ameghino’s apparent discovery that all basal mammals evolved in South America led him to believe that human evolution likewise took place on the continent. He developed a complete phylogenetic tree of human history for South America without seeing any evidence. He even classified several genera of proto-humans he had yet to actually find. This work also lacked any reference to geologic time. But in a few years following this publication, Ameghino suddenly announced his discovery of many of his hypothesized forms. He had discovered that humans had, after all, evolved in South America.2

Ameghino had several fossils that backed his claims. He discovered a human femur that he dated to the Miocene (more than 5 million years ago), a piece of a skull that came from Pliocene deposits (around 2-5 million years ago), and several other skulls and human remains that came from around Argentina from similarly-aged deposits. However, neither he nor his brother discovered any of these fossils in the field, instead most came from the museums archives or were given to Ameghino.2

A sketch of a damaged human skull with four different views of the same skull.
Sketches made of one of the fossil human Ameghino was certain was Late Pliocene in age (around 3-4 million years old). Recent dating suggests it is from a modern human from possibly around 2000 years ago.4?

Ameghino’s complex human evolutionary tree was quickly filled in by the many remains in the museum. He used detailed measurements of the bones to prove they were from ancient human relatives and not from modern Homo sapiens. They were millions of years older than the oldest known human remains in South America, and were older than any human ancestors found to that date in Africa.

But they are clearly wrong, and Ameghino’s detractors were quick to pounce on him for it. Instead, many of the Euro-American establishment noted that the fossils looked identical to modern humans, and likely came from more recent deposits following the established theory of the migration of Homo sapiens into South America. This assessment was confirmed by a more recent study which carbon dated some of Ameghino’s specimens. They range in age from 200 to 10,000 years old, well within the established migration dates of modern humans into South America. One fossil he thought was the oldest and most primitive (the skull fragment shown below) turned out to be only about 250 years old!5

Diprothomo platensis, one of the supposed early hominid skulls Ameghino described, (Image: Aleš Hrdlička, “Early Man in South America book). Others considered this to be just a fragment of a modern Homo sapiens, which recent carbon dating has confirmed.4

How, then did Ameghino get so wrong? Many contemporary paleontologists even agreed with Ameghino that his mammal fossils were basal relatives of many other orders observed elsewhere, and that he had his evolutionary succession mostly correct. Instead, there was consensus amongst the established community that Ameghino was completely wrong on his ages. After many other paleontological teams came to Argentina to investigate, they all came to a different stratigraphic interpretation that the finds were much younger (and ultimately correct).2

Ameghino defied this interpretation claiming it was biased by the Euro-American outlook on paleontology that they were more used to in the Northern Hemisphere. Eventually, more people travelled out to Ameghino’s fossil sites and all came to the same conclusion: Ameghino had his stratigraphy essentially turned upside down. The rocks the mammals came from were much younger, Miocene and Pliocene-aged deposits (around 5-20 million years old), and the Cretaceous was below them, not above the units as Ameghino had so adamantly believed.2

What do we make of Ameghino? He clearly made some astounding discoveries that disproved the very biased view that evolution only took place in the northern hemisphere. At the same time he was completely wrong on the ages of his finds, and he misidentified more recent human remains as ancient human ancestors.

In my next post, I’ll go into more detail about why Ameghino was so wrong. We will also look at the evidence that may suggest he did so willingly in order to essentially fight back against colonial nature of paleontology.

Florentino was a paleontological giant, befitting of the “Land of Giants”, Patagonia, in which he made his discoveries. He also should be lauded for his attempts to decolonize paleontology in Argentina. But, like I will talk about next time, he is also a complicated figure who made some key mistakes that forever marred his legacy.


  1. Hrdlička, A., 1912. Early Man in South America (Vol. 52). US Government Printing Office.
  2. Podgorny, I. (2005). Bones and devices in the constitution of paleontology in Argentina at the end of the nineteenth century. Science in context18(2), 249-283.
  3. Simpson, G.G., 1985. Discoverers of the lost world: an account of some of those who brought back to life South American mammals long buried in the abyss of time. Journal of the History of Biology, 18(3).
  4. Vizcaíno, S.F., De Iuliis, G., Brinkman, P.D., Kay, R.F. and Brinkman, D.L., 2017. On an album of photographs recording fossils in the” old collections” of the Museo de La Plata and Ameghino’s private collection at the beginning of the XXth century. Publicación Electrónica de la Asociación Paleontológica Argentina17.
  5. Politis, G.G., 2011. Nuevos datos sobre el “hombre fósil” de Ameghino. Publicación Electrónica de la Asociación Paleontológica Argentina, 12(1).

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