A worn-down leopard seal enamel (#CN47208, Lot 303). Credit score: Sandee Oster
Waterfall Bluff Rock Refuge (WB) (Japanese Cape Province (ECP), South Africa) comprises archaeological deposits demonstrating power and steady human profession spanning from Overdue Marine Isotope Degree 3 (~39ka–29ka) to the mid-Holocene (~8ka). It’s at this website online that the primary leopard seal (Hydrurga leptonyx) specimen used to be not too long ago recovered from a Pleistocene and Holocene zooarchaeological assemblage alongside South Africa’s coast.
Our paper is revealed within the South African Magazine of Science.
Leopard seal ecology
Leopard seals are apex marine predators whose habitats are in most cases limited to the pack ice within the Antarctic and sub-Antarctic islands. They require pack ice to ambush their prey, the vast majority of which is made up of krill; on the other hand, they’re additionally identified to seek penguins, pinnipeds, fish, and cephalopods.
In fashionable instances, there were just a handful of sightings from South Africa, each useless and alive, of leopard seals, with probably the most earliest being in 1946 in East London within the Japanese Cape Province (ECP). A 2d sighting used to be revamped two decades later at Hout Bay in 1969.
A useless leopard seal used to be reported to the East London Museum (ECP) in 1994, and extra not too long ago, a dwelling specimen used to be sighted at Cove Rock (ECP) in 2014. The latest sighting used to be in 2021, the place a dwelling person used to be noticed two times, as soon as in Cape The town and once more in Yzerfontein (Western Cape Province), earlier than sightings ceased.
Just lately, we found out a leopard seal enamel from a deposit relationship to the Remaining Glacial Most (LGM) (22,560–19,340 cal. BP) at WB. This makes it the primary leopard seal to be recovered from a Pleistocene and Holocene zooarchaeological assemblage alongside South Africa’s coast.
Figuring out the website online and the invention
WB is situated round 24m above the trendy beach subsequent to the Mlambomkulu River waterfall, ECP. It’s been divided into two steady layers of sediment, specifically the Gentle Brown Coarse Sands (LBCS) dated to between 37,6±4,2ka and the Shell-Wealthy Clayey Sands (SRCS) dated via Bayesian 14C accelerator mass spectrometry type from ~11ka cal BP to ten,5ka cal BP.
What makes this website online specifically vital is its constant proximity to the coastline all over each glacial and interglacial sessions.
Southern Africa these days has few coastal archaeological websites relationship to the Terminal Pleistocene; even if people occupied such websites on the time, many had been destroyed or stay undiscovered. This shortage is because of consistent sea-level fluctuations, which ended in a bias in opposition to conserving coastal archaeological information all over glacial sessions.
On the other hand, owing to WB’s positioning adjoining to an exceptionally slender continental shelf, it has survived and preserves information documenting repetitive human profession spanning millennia. This website online would had been particularly fascinating to people because of its nearness to the coast, offering marine meals and get right of entry to to more than one terrestrial sources.
It’s been hypothesized that such websites would had been occupied in other places in southern Africa via people, reminiscent of via the Palaeo Agulhas Undeniable. On the other hand, those information at the moment are underwater, making WB considered one of only some websites offering insights into human profession and behaviour all over glacial and inter-glacial sessions.
We record on our initial effects on faunal analyses undertaken in 2021 and their implications for the paleoenvironment at WB. Even supposing our pattern measurement is small, the interpretations supply compelling insights into native paleoenvironments and human exploitation conduct.
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The paleoenvironment at WB and its implications
The website online presentations proof of a power mosaic atmosphere in a position to reinforce all main plants sorts and systematically exploiting each marine and terrestrial sources via hunter–gatherers all over.
The website online’s location and solid atmosphere would have made it particularly fascinating to are living in, as hunter–gatherers would have had more than a few sources at their disposal irrespective of the encompassing atmosphere.
The presence of more than a few terrestrial mammals in each SRCS and LBCS layers that require other habitats to live on, reminiscent of Eland (Taurotragus oryx), duiker (Sylvicapra grimmia), and African massive buffalo (Syncerus afer), point out the lifestyles of blended, furry and grassland environments all over the profession of the website online.
Moreover, the presence of fish, seals, shellfish, and conceivable barnacle stays within the earliest deposit (LBCS) signifies that individuals had been actively harvesting from the coast even if it used to be most likely ~8km away all over glacial instances. This power use of marine sources demonstrates the significance of coastal environments to early human communities, even all over sessions when the coast used to be additional away, and it will have most likely required extra effort to shuttle to the coast to obtain sources.
We recognized a leopard seal enamel from this LBCS deposit. The enamel used to be recognized via its unique triple-cusped crown, which is used for sieving krill, distinguishing it from the tooth of the extra commonplace fur seal in most cases discovered within the area.
Leopard seals are extremely dependent at the frigid waters surrounded via pack ice for his or her survival, no longer just for searching but in addition for breeding and meals functions. People who stray too some distance from their house levels are in most cases misplaced juveniles or ravenous and unwell.
Whilst it’s conceivable that this leopard seal used to be one such misplaced person, taking into account that native sea floor temperatures had been, on moderate, 3°C less than present ranges, the stipulations will have been appropriate for those Antarctic predators to increase their vary northward.
The larger pack ice on account of such low temperatures in northerly levels and the reducing off of particular krill spawning websites in Antarctica will have compelled and enabled some leopard seals to happen a lot nearer to the South African coast than nowadays. Moreover, the website online’s proximity to a river mouth would have washed inland vitamins into the sea and may have helped take care of ocean vitamins that supported the marine animals upon which leopard seals preyed.
Making an allowance for that all over those glacial instances, WB would had been round 8km from the coast, the leopard seal enamel would have needed to be introduced into the refuge via people. The presence of the leopard seal enamel indicated a far less warm local weather and might also point out that people had been a lot more aware of those animals all over the LGM, sufficient to acquire it and delivery it, most likely as sustenance to their refuge.
The procurement of all of the above animals additionally would possibly trace at how adaptable and numerous the subsistence behaviors of early hunter–gatherers had been, the use of the sources introduced via predator and prey species.
This tale is a part of Science X Conversation, the place researchers can record findings from their revealed analysis articles. Talk over with this web page for details about Science X Conversation and the way to take part.
Additional information:
Sandee Oster et al, Overdue Pleistocene and Holocene fauna from Waterfall Bluff Rock Refuge, Mpondoland, South Africa, South African Magazine of Science (2024). DOI: 10.17159/sajs.2024/17449
I’m a Ph.D. candidate on the College of the Witwatersrand; since 2018, I’ve been learning archaeology with a focal point on zooarcheology, rock artwork, and isotopes. My pursuits lie in uncovering the interaction between people & animals all over historical past. I search to advance present analysis at the 8.2k tournament in South Africa and give a contribution to filling a considerable wisdom hole with my paintings. I’m actively operating in opposition to publishing my doctoral analysis findings & presenting my paintings at educational meetings within the hopes of changing into a well-rounded and the world over known archaeological researcher.
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Paleoenvironmental learn about at Waterfall Bluff finds leopard seal some distance from Antarctic waters (2024, December 14)
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