Historical poop gives uncommon perception into animal behaviour

Some persons are aggravated once they encounter a recent pile of dung whereas out on a stroll in nature. Others are excited as a result of it factors to the latest go to of a specific sort of animal. However some scientists, myself included, could be disenchanted that the dung isn’t fossilised.

That’s as a result of coprolites – fossilised scat – are palaeontological treasure troves. They’ll present all kinds of details about the animal that deposited them, together with the atmosphere they lived in, what they ate and what the local weather and vegetation had been like.

Over the previous decade, our analysis group has recognized greater than 300 vertebrate tracksites in aeolianites (cemented sand dunes) and cemented seaside deposits on the Cape south coast of South Africa. They date again to the Pleistocene epoch, which began about 2.6 million years in the past and ended round 11,700 years in the past. However it took us a very long time to grasp that we shouldn’t simply be in search of depressions (tracks) within the rock surfaces we research; we must also be looking out for raised options. These, it seems, are sometimes coprolites.

In a recent paper we describe a variety of firsts. Our findings are the primary of their variety from southern African aeolianites. We’ve additionally recorded the primary identified cases of coprolites belonging to a Nile crocodile, and to an African elephant. And we found a website the place roaming elephants could have repeatedly disturbed small animals, in all probability mongooses or genets, that had been answering the decision of nature.

These discoveries, together with our earlier analysis, mix to create an image of an historic panorama so scientists can higher perceive what got here earlier than. Trying again may assist us perceive how and when issues modified and what function components like local weather or the arrival of people performed in these modifications.

The brand new websites

It took one notably apparent instance to alert us to what we had been lacking by not contemplating coprolites as research materials. On an aeolianite floor close to the city of Knysna, about 500km from Cape City, we noticed 130 darkish nodules, between 2cm and 3cm in dimension. They shaped a transparent distinction to the a lot lighter surrounding floor, on which 4 tracks of a medium-sized bovid (in all probability an antelope referred to as a bontebok) had been evident.

Learn extra: My job is full of fossilised poop, but there’s nothing icky about ichnology

The nodules had been evenly unfold over a distance of greater than a metre, and a few them truly lay throughout the tracks. They had been barely flattened, suggesting that that they had been frivolously compressed by overlying dune layers whereas they had been nonetheless malleable. A pattern for courting from a close-by rock revealed that the positioning was round 76,000 years previous.

It was our first coprolite website and it was an unprecedented discovering. Bovid coprolites are extraordinarily uncommon and an open-air website much more so. In southern Africa, coprolites are normally present in caves and rock shelters, in scavenger dens or archaeological deposits.

Additionally, we had luck on our aspect: the positioning is normally coated by metres of sand, and is just often uncovered.

Remarkably, shut by we discovered a second website, however with very completely different traits. On this case we famous about 50 small tracks on a rock floor, on which had been plastered about 30 raised options, lots of which had been cylindrical and hole (attribute options of some coprolites). Within the low cliffs instantly above this floor we discovered related coprolites in six layers in a vertical peak of two.6cm.

The proof was clear: this was the positioning of a latrine (a spot that an animal returns to repeatedly to defecate), which had been used for a considerable time period. We couldn’t determine the tracks to household stage, as many small carnivorans go away tracks which can be related in dimension and form. Nevertheless, the character of the latrine suggests {that a} genet or mongoose may need been accountable.

So as to add to the curiosity, deep elephant tracks had been a standard phenomenon on these similar surfaces, main us to think about the latrine-maker having to dodge trampling by African elephants at indelicate moments.

Extra evaluation wanted

We discovered two different coprolite websites. One featured each African elephant tracks and coprolites – the primary of their variety ever described. The opposite offered us with a crocodile coprolite proper beside crocodile swim traces. That is the primary ever document of a Nike crocodile coprolite; it was in all probability deposited underwater in a shallow lagoonal atmosphere (crocodiles defecate both on land or in water).

We despatched samples to college laboratories for various checks, together with evaluation of pollen and phytoliths (microscopic silica buildings present in vegetation). Optimistic outcomes would have aided in serving to us interpret the Pleistocene atmosphere and local weather. Sadly, as usually occurs, all our coprolites had been “sterile”, with no pollen or phytoliths to be discovered.

Our response is to maintain making an attempt: in 2022 we recognized a variety of different coprolites on the identical shoreline, together with these of the extinct long-horned buffalo. These seem to have extra inside construction, which augurs effectively for detecting phytoliths and pollen, and even perhaps proof of bone fragments within the case of carnivores.

We hope that the samples we submit this time will ship extra constructive outcomes and can shed new mild on the Pleistocene palaeoenvironment of coastal southern Africa.