The Chamacoco display an extraordinary multiplicity of types. More to the east, the characters of the Botocudo type probably tend to prevail, not without more or less sensitive mixes with the Bororo type. Thus the Guayaki of the western bank of the upper Paraná, with their physiognomic features, with their small stature, are probably similar to the Botocudo. Probably also the Caingua, of the same region, more numerous, have an anthropological relationship with this type.
In this whole area, as in the neighboring provinces of Brazil, very probably there must have been mixtures of the element Botocudo with the element Bororo, since this is present in the Sambaqui, according to Sera; but above the Botocudo another stratification must have occurred, represented by the Guarani people, perhaps of the type that we have called Caribo-arovacco-Tupi. In the west, however (lower Bolivia, above all) the Bororo type was mixed with the predominant Yamamadi type.
Most of the prehistoric populations, which we will soon see, of the middle and lower basin of the Paraná (except the Guarani) are probably to be considered as forms of development of a Yamamadi type, with less or greater access of Bororo blood.
Moving to the south, the Andean provenance is certain for the so-called Argentine Araucani, whose craniological characters are similar to those of the Chilean Araucani. They were driven back to the south of the Río Negro. It is not unlikely that in this region there are also residues of the population that inhabited the Argentine territory before the conquest.
Regarding this and the most ancient populations, the data of contemporary chroniclers or those who lived in the first times of the conquest, if they provide discreet elements for ethnography, give us few anthropological explanations. Moreover, even with regard to ethnic groups who have recently disappeared, we know little for sure. Thus, to cite the example of an ethnic group from Uruguay, who disappeared in the first half of the last century, the Charrua, it is hardly known that they had a very dark complexion and rather tall stature (1.68 m.).
Torres, in his work cited below, has recently collected and significantly expanded (with his own research in Argentine archives) the data collected by historical critics on the most salient physical traits of the indigenous people of Argentina and the surrounding regions. However, the indications left by chroniclers and travelers from the time of the conquest onwards, especially as regards the early times, are very vague and do not usually capture anthropological characteristics of good discriminative value. What is perhaps most interesting is what results from the geographical location of the Guarani ethnic groups and their stature. These seem to have been located, at the time of the conquest, above all in Paraguay, Misiones and neighboring territories of Brazil. However, it seems that the Guarani were also very numerous in the islands of the lower Delta and in the territory of Santa Fe. The testimonies of almost all chroniclers attribute them to small stature, in comparison with other populations. It may be that they in the south, in the province of Buenos Aires, were only a passing element.
The other populations, along the middle and lower reaches of Paraná, and between Paraná and Uruguay, are generally considered to be tall, robust and beautiful (Chaná-Timbú-Beguá, Querandí, Charrua, Minuane).
The same applies to the groups of the upper basin of Uruguay and Paranà (Arechane, Ariyo, Guayana. Etc.), almost all belonging to the Gês division.
This similarity in tall stature, however, let’s face it immediately, has little meaning in establishing affinity between the former and the latter. On the contrary, the indigenous people of much of Uruguay were of medium height, and it should be remembered that many of their ethnographic characteristics do not coincide with those of the indigenous people of the middle and lower Paraná, mentioned above, despite the proximity.
We advance the hypothesis, moreover supported by more than one fact, that they represented remains of a primitive Gês layer on the region.
In times closer to us, Orbigny gave a physical characteristic of the Guarani, from which we derive some other character, which can be considered well observed, namely: more rounded skull, very broad chest, generally massive trunk, hands and feet little ones.
Turning now to material that is actually safer, because it is based on the bone remains left by ancient populations, the anthropology of the ancient Calchaqui is known mainly thanks to the research of Ten Kate. There is no doubt that most of the population belonged to the Andean Quechúa type; the characters of the face, the brachycephaly, the small stature put this out of the question. This suggests, given that the Diaguita region is on the eastern side of the Andes, that the Andean type Quechúa may have also populated the lowlands of northern Argentina in some time or at least provided elements to its population.
Moreover, this would only be the repetition of the same fact, known further south, of the passage of the Chilean Araucanians in Argentina; being the type of the Araucani almost the Quechúa type. The passage of the Araucani in Argentina, however, is relatively recent, having perhaps occurred shortly after the conquest.
Torres’ very extensive study of osteological material, coming from mounds and cemeteries of the primitive residents of the Paranà Delta, offers interesting data. The mound no. 1 of the Brazo Gutiérrez contains, among others, a short and high skull, which has characters on the face that suggest the Quechúa type. But in the same mound we have the presence of a skull of the Botocudo type, and of others certainly indicating mixtures.
In another cemetery (# 1 Paraná Guazú) we have a fairly good Bororo type skull. In almost all tumuli and cemeteries, where at least it is possible to ascertain it, the existence of a low-skulled type (platicephalic) can be assured.
Therefore, even in these finds, we have evidence of the existence of several human types forming the same ethnic group. Certainly, to arrive at simpler anthropological conditions in the region, it is necessary to go back to much older times.