Evidence for size increase in an exploited mollusc: humped conch (Strombus gibberulus) at Chelechol ra Orrak,Palau from ca. 3000–0 BP

Past research has suggested that the humped conch (Strombus gibberulus), a species common in many prehistoric archaeological sites in the Pacific, declines in size and/or abundance over time. Explanations for this phenomenon largely revolve around the possibility that they were overharvested by human populations. In this study, we measured the length and width of over 1400 individual specimens of S. gibberulus shells recovered from the site of Chelechol ra Orrak in Palau, western Micronesia, in deposits dating from ca. 3000 BP to the present. Statistical analysis indicates that in contrast to previous reports, there is a significant size increase for this taxon through time which may be the result of a combination of anthropogenic and environmental factors. We discuss variables influencing mollusc size and suggest that, given the complexities of their interactions and the data limitations of archaeomalacological assemblages, unambiguous determination of the cause(s) of molluscan size change may not always be possible.     

Evidence for inter-island transport of heirlooms: luminescence dating and petrographic analysis of ceramic inhaling bowls from Carriacou,West Indies

Ceramic snuffing tubes and inhaling bowls used for ingesting hallucinogenic substances are known from several islands in the West Indies, but their chronological distribution is often vague. A partial inhaling bowl found at the site of Grand Bay on Carriacou in deposits dating between ca. A.D. 1000–1200, along with two other unprovenienced specimens from the local museum, were dated using luminescence (TL and OSL) to determine their antiquity. Surprisingly, the dates had a weighted average of 400 ± 189 B.C., making them several hundred years older than all ¹⁴C assays from the island; however, they do overlap in age with similar artifacts found on Puerto Rico and Vieques Island over 750 km away. Additional luminescence dating of two stylistically distinct Suazan ceramic sherds excavated from stratified deposits at Grand Bay fall within the expected ceramic and radiocarbon chronology. These data, coupled with petrographic analysis of the specimens, suggests that they were not made using local materials. Instead, they appear to have been transported to the island, possibly hundreds of years later, as heirlooms. This may be the first evidence for inter-island transport of drug paraphernalia in the Caribbean.     

Examining dispersal mechanisms for the translocation of chicken (Gallus gallus) from Polynesia to South America

DNA sequencing and radiocarbon dates from the archaeological site of El Arenal-1 (Arauco Peninsula, south central Chile) suggest that Polynesians may have introduced chicken (Gallus gallus) to South America prehistorically (A.D. 1300–1420). The Chilean specimen identified has the exact same amplified mtDNA pattern as samples recovered from archaeological sites in Samoa and Tonga, but is only one base different from prehistoric chicken samples from Tonga (n = 1), Niue (n = 1), Easter Island (n = 1 of 6), and Hawai'i (n = 1). To examine the possible dispersal mechanisms of chicken between Polynesian islands and the Americas, we conducted computer simulations of seafaring from these six island groups and the Tuamotus, as well as return voyages. Simulation results from sailed vessels suggest that in certain months, landfall on the Pacific Coast of South America from Samoa and Tonga was fairly successful at around 40% (particularly in March for the former and January/February for the latter). For Niue, sailed vessels were 21% successful in January with only 2% success in December. Sailed vessels from the Tuamotus (a proxy for closer island groups to the west with evidence for chicken such as the Cook Islands) were successful in January and December, with 15% and 23% of the vessels making landfall in South America. Vessels sailing from all simulations heading east from Easter Island resulted in landfall. Hawai'i had only a 1% success rate if sailing in January, but high numbers of vessels reached southern Mexico and Central America in August and September. Most landfalls occurred much farther north than Chile, in Ecuador and Peru. Unsuccessful voyages from all of the islands other than Easter Island and Hawai'i often made landfall on islands to the east. Return voyages from Chile were not possible or extremely rare during most times of the year. Overall, seafaring simulations suggest that Polynesians may not have initially landed in close proximity to El Arenal-1—contemporaneous or even earlier archaeological evidence of translocated chicken remains may indeed be found further north. In addition, if Polynesians found it difficult or impossible to return to their homeland, the possibility exists that co-mingling between Polynesians and South American groups resulted in offspring that carried an admixture of genetic traits.     

Seafaring Capabilities in the Pre-Columbian Caribbean

At historic contact Europeans remarked on the skill and proficiency of native Caribbean Amerindians to build and travel in dugout canoes. While archaeological examples of these have been recorded throughout the circum-Caribbean, very few exist in the Antillean chain of islands. Despite this deficiency, indirect evidence of seafaring along with archaeological data has suggested to many that the sea was an artery that linked prehistoric communities together between islands and continents through exchange networks and settlement ‘lifelines’. It is clear that frequent interaction was taking place prehistorically in the region, but examination of seafaring capabilities and the general lack of hard archaeological evidence for contacts in many places suggest this was largely restricted to interaction between the islands and with South America. The fact remains that seafaring in the Caribbean, as one of the smaller aquatic realms inhabited by humans in the past, was highly influenced and largely structured by oceanographic and anemological effects that limited the development of various watercraft designs and navigational techniques which are seen in many of the other world’s seas and oceans. In this paper I: (1) synthesize what is currently known about the antiquity and development of early seafaring in the Caribbean; (2) highlight debates about the level of technologies found in the region; (3) discuss how environmental conditions likely influenced seafaring capabilities and settlement patterns; (4) outline the possible evidence for connections between the different surrounding mainland areas; and (5) provide a comparison with seafaring technologies found in the Pacific to help contextualize the Caribbean into the broader context of global seafaring.     

Intensifying collection and size increase of the tessellated nerite snail (Nerita tessellata) at the Coconut Walk site,Nevis, northern Lesser Antilles,AD 890–1440

Recent archaeological investigation at the Coconut Walk site on the Caribbean island of Nevis revealed dense 40 cm deep midden deposits that accumulated between cal AD 890–1440. Analysis of invertebrate faunal remains reveals an assemblage dominated by nerite snails. We measured the length and width of more than 2700 tessellated nerite (Nerita tessellata) shells to investigate evidence for changing mean size that might be indicative of intensifying human predation pressure or other cultural and natural processes. Contrary to similar archaeomalacological studies in which size decline is detected, we observed a statistically significant size increase for N. tessellata over time. This size increase is coupled with increasing levels of tessellated nerite exploitation at the Coconut Walk site. Results suggest that tessellated nerite use was sustainable over several centuries of site occupation. Our findings have important implications for investigations of anthropogenic impacts on prehistoric mollusc populations. In addition, the findings reported here provide important insight into human subsistence patterns during the Late Ceramic Age in the Caribbean and a framework for comparison with observations from other Pre-Columbian sites in the Caribbean.     

δ18O Analyses of the Humpbacked Conch (Gibberulus gibberulus): Evaluating a Proxy for Reconstructing Sea-Surface Temperature at Chelechol ra Orrak,Palau

ABSTRACT

In Palau, Micronesia, marine resources, particularly shellfish, played a vital role in human subsistence for millennia. Despite the vast array of molluscan species in archaeological assemblages, there is a dearth of data on nearshore palaeoecology or prehistoric shellfish foraging practices. In this study, we analysed stable oxygen isotopes (δ¹⁸O) values present in the calcium carbonate shell of Gibberulus gibberulus from the Chelechol ra Orrak archaeological site to reconstruct average nearshore sea-surface temperatures (SST) from approximately 1500–1100 cal BP. Modern shellfish samples and environmental data were collected from intertidal zones near the site and x-ray diffraction (XRD) was employed to identify the biomineralogical composition of G. gibberulus. These steps provide necessary information for the selection of the proper oxygen isotope-to-SST conversion formula. The selected formula was applied to δ¹⁸O samples from archaeological shells to reconstruct prehistoric SST averages. The results of this proxy validation study verify that G. gibberulus accurately records ambient SST and can be used to reconstruct ancient nearshore conditions. These findings also contribute to the establishment of an environmental baseline, which can be used to examine how environmental changes may have influenced the availability of molluscan taxa that in turn influenced human subsistence practices through time.