New fossil sea turtle trackway morphotypes from the Pleistocene of South Africa highlight role of ichnology in turtle paleobiology

2019 ◽  
Vol 92 (3) ◽  
pp. 626-640 ◽  
Author(s):  
Martin G. Lockley ◽  
Hayley C. Cawthra ◽  
Jan C. De Vynck ◽  
Charles W. Helm ◽  
Richard T. McCrea ◽  
...  
Keyword(s):  
South Africa ◽  
Late Pleistocene ◽  
Sea Turtles ◽  
Loggerhead Turtle ◽  
Sea Turtle ◽  
Climatic Conditions ◽  
South Coast ◽  
Freshwater Turtles ◽  
Leatherback Turtle

AbstractMore than 130 late Pleistocene trackway sites from the coastal eolianites and beach deposits of the Cape south coast, South Africa, have previously mostly yielded tracks of large mammals and birds. However, two sites east of Still Bay, and a third near Garden Route National Park, yield distinctive trackways of hatchling sea turtles, made during the short posthatching (postemergence) interval when the trackmakers headed for the sea. One assemblage of approximately parallel trackways indicates smaller loggerhead turtle hatchlings, with alternating gaits, and contrasts with a wider trackway indicating a leatherback turtle hatchling. These are the world's first reports of fossil traces that document this brief “run-for the-sea” phenomenon. They help delineate late Pleistocene sea turtle breeding ranges and indicate climatic conditions along the Cape south coast. Ichnotaxonomically defined swim tracks of large adult sea turtles are known from a few Mesozoic sites. Likewise, walking and swim traces of terrestrial freshwater turtles are also known from the Mesozoic and Cenozoic. However, as no ichnotaxonomy exists for these diagnostic hatchling trails, we assign the trackways of the inferred loggerheads to the new ichnotaxon Australochelichnus agulhasii ichnogen. et ichnosp. nov., and the inferred leatherback trackway to Marinerichnus latus ichnogen. et ichnosp. nov.

scholarly journals Interannual Differences for Sea Turtles Bycatch in Spanish Longliners from Western Mediterranean Sea

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
José C. Báez ◽  
David Macías ◽  
Salvador García-Barcelona ◽  
Raimundo Real
Keyword(s):  
Mediterranean Sea ◽  
Loggerhead Turtle ◽  
Sea Turtle ◽  
Western Mediterranean ◽  
Climatic Conditions ◽  
Fishing Activity ◽  
Leatherback Turtles ◽  
Leatherback Turtle ◽  
Western Mediterranean Sea ◽  
Loggerhead Turtles

Recent studies showed that regional abundance of loggerhead and leatherback turtles could oscillate interannually according to oceanographic and climatic conditions. The Western Mediterranean is an important fishing area for the Spanish drifting longline fleet, which mainly targets swordfish, bluefin tuna, and albacore. Due to the spatial overlapping in fishing activity and turtle distribution, there is an increasing sea turtle conservation concern. The main goal of this study is to analyse the interannual bycatch of loggerhead and leatherback turtles by the Spanish Mediterranean longline fishery and to test the relationship between the total turtle by-catch of this fishery and the North Atlantic Oscillation (NAO). During the 14 years covered in this study, the number of sea turtle bycatches was 3,940 loggerhead turtles and 8 leatherback turtles, 0.499 loggerhead turtles/1000 hooks and 0.001014 leatherback turtles/1000 hooks. In the case of the loggerhead turtle the positive phase of the NAO favours an increase of loggerhead turtles in the Western Mediterranean Sea. However, in the case of leatherback turtle the negative phase of the NAO favours the presence of leatherback turtle. This contraposition could be related to the different ecophysiological response of both species during their migration cycle.

The role of ostrich in shaping the landscape use patterns of humans and hyenas on the southern coast of South Africa during the late Pleistocene

2018 ◽  
pp. 333-346 ◽  
Author(s):  
Jamie Hodgkins ◽  
Petrus le Roux ◽  
Curtis W. Marean ◽  
Kirsty Penkman ◽  
Molly Crisp ◽  
...  
Keyword(s):  
South Africa ◽  
Late Pleistocene ◽  
Southern Coast ◽  
Use Patterns ◽  
Landscape Use

scholarly journals Southern Hemisphere anticyclonic circulation drives oceanic and climatic conditions in late Holocene southernmost Africa

2017 ◽  
Vol 13 (6) ◽  
pp. 649-665 ◽  
Author(s):  
Annette Hahn ◽  
Enno Schefuß ◽  
Sergio Andò ◽  
Hayley C. Cawthra ◽  
Peter Frenzel ◽  
...  
Keyword(s):  
South Africa ◽  
Climatic Conditions ◽  
Sea Surface ◽  
South Coast ◽  
Ice Age ◽  
Sea Surface Temperatures ◽  
The South ◽  
Anticyclonic Circulation ◽  
Surface Temperatures ◽  
Precipitation Regimes

Abstract. Due to the high sensitivity of southern Africa to climate change, a reliable understanding of its hydrological system is crucial. Recent studies of the regional climatic system have revealed a highly complex interplay of forcing factors on precipitation regimes. This includes the influence of the tropical easterlies, the strength of the southern hemispheric westerlies as well as sea surface temperatures along the coast of the subcontinent. However, very few marine records have been available in order to study the coupling of marine and atmospheric circulation systems. Here we present results from a marine sediment core, recovered in shallow waters off the Gouritz River mouth on the south coast of South Africa. Core GeoB18308-1 allows a closer view of the last  ∼  4 kyr. Climate sensitive organic proxies, like the distribution and isotopic composition of plant-wax lipids as well as indicators for sea surface temperatures and soil input, give information on oceanographic and hydrologic changes during the recorded time period. Moreover, the micropaleontology, mineralogical and elemental composition of the sediments reflect the variability of the terrigenous input to the core site. The combination of down-core sediment signatures and a catchment-wide provenance study indicate that the Little Ice Age ( ∼  300–650 cal yr BP) was characterized by climatic conditions favorable to torrential flood events. The Medieval Climate Anomaly ( ∼  950–650 cal yr BP) is expressed by lower sea surface temperatures in the Mossel Bay area and humid conditions in the Gouritz River catchment. These new results suggest that the coincidence of humid conditions and cooler sea surface temperatures along the south coast of South Africa resulted from a strengthened and more southerly anticyclonic circulation. Most probably, the transport of moisture from the Indian Ocean by strong subtropical easterlies was coupled with Agulhas Bank upwelling pulses, which were initiated by an increase in Agulhas Current strength.

Nesting failure of sea turtles in Ecuador - causes of the loss of sea turtle nests: the role of the tide

2020 ◽  
Vol 24 (5) ◽  
Author(s):  
Antonio José Carpio Camargo ◽  
Yamel Álvarez Gutiérrez ◽  
Julio Jaramillo Véliz ◽  
Francisco Sánchez Tortosa
Keyword(s):  
Sea Turtles ◽  
Sea Turtle

Tursiocola neliana sp. nov (Bacillariophyceae) epizoic on South African leatherback sea turtles (Dermochelys coriacea) and new observations on the genus Tursiocola

Phytotaxa ◽  
2020 ◽  
Vol 453 (1) ◽  
pp. 1-15 ◽  
Author(s):  
ROKSANA MAJEWSKA
Keyword(s):  
Sea Turtles ◽  
Central Area ◽  
Sea Turtle ◽  
Dermochelys Coriacea ◽  
Eastern Coast ◽  
New Taxon ◽  
Freshwater Turtles ◽  
Diatom Genus ◽  
Leatherback Sea Turtles ◽  
Internal Side

Tursiocola, a presumably exclusively epizoic diatom genus, comprises species found on various aquatic animals such as cetaceans, manatees, and marine and freshwater turtles. The genus is characterised by linear or lanceolate valves with well-developed pseudosepta at both poles, a valvocopula with three pairs of siliceous tabs, and a butterfly-like structure extending from the central nodule on the internal side of the valve. The current study describes a novel species of Tursiocola, T. neliana Majewska sp. nov. that grows epizoically on leatherback sea turtles from the Eastern Coast of South Africa based on detailed observations using light and scanning electron microscopy. The new taxon resembles the other currently known sea turtle-associated Tursiocola species in possessing relatively small, slightly heteropolar valves with acute apices and a strongly reduced butterfly structure on the internal side. However, T. neliana differs from all other members of the genus in being distinctly dorsiventral, with a clearly bowtie-shaped central area, unequal stria density on two sides of the raphe-sternum, and up to 8 areolae per stria. The description of the new taxon brings the total number of the sea turtle-associated Tursiocola species known so far up to four. An emended description of Tursiocola is proposed based on the new observations presented in this and other recent reports. Furthermore, the current understanding of the genus ecology is summarised.

scholarly journals Checklist of sea turtles endohelminth in Neotropical region

2016 ◽  
Vol 53 (3) ◽  
pp. 211-223 ◽  
Author(s):  
M. R. Werneck ◽  
R. J. Da Silva
Keyword(s):  
Sea Turtles ◽  
Loggerhead Turtle ◽  
Chelonia Mydas ◽  
Neotropical Region ◽  
Dermochelys Coriacea ◽  
Olive Ridley ◽  
Eretmochelys Imbricata ◽  
Leatherback Turtle ◽  
Lepidochelys Olivacea ◽  
The Caribbean

SummaryThis paper presents a list of parasites described in sea turtles from the Neotropical region. Through the review of literature the occurrence of 79 taxa of helminthes parasites were observed, mostly consisting of the Phylum Platyhelminthes with 76 species distributed in 14 families and 2 families of the Phylum Nematoda within 3 species. Regarding the parasite records, the most studied host was the green turtle (Chelonia mydas) followed by the hawksbill turtle (Eretmochelys imbricata), olive ridley turtle (Lepidochelys olivacea), loggerhead turtle (Caretta caretta) and leatherback turtle (Dermochelys coriacea). Overall helminths were reported in 12 countries and in the Caribbean Sea region. This checklist is the largest compilation of data on helminths found in sea turtles in the Neotropical region.

scholarly journals Marine Mammal and Sea Turtle Sightings During a Survey of the Endeavour Segment of the Juan de Fuca Ridge, British Columbia

2017 ◽  
Vol 131 (2) ◽  
pp. 120-124
Author(s):  
Meike Holst
Keyword(s):  
British Columbia ◽  
Marine Mammals ◽  
Current Knowledge ◽  
Sea Turtles ◽  
Sperm Whale ◽  
Sea Turtle ◽  
Elephant Seal ◽  
Physeter Macrocephalus ◽  
Northern Elephant Seal ◽  
Leatherback Turtle

Marine mammals and sea turtles were documented as part of a monitoring and mitigation program during a seismic study offshore (~250 km) from Vancouver island, British Columbia, during August–September 2009. Forty-one marine mammals in nine groups were sighted. Dall’s Porpoise (Phocoenoides dalli) was the most frequently sighted species. A Sperm Whale (Physeter macrocephalus), a pod of Pacific White-sided Dolphins (Lagenorhynchus obliquidens), an unidentified toothed whale, a Northern Elephant Seal (Mirounga angustirostris), and a leatherback Turtle (Dermochelys coriacea) were also observed. These data augment current knowledge on the occurrence of marine mammals and sea turtles in the offshore waters of British Columbia.

Pollen Analysis of Hyena Coprolites and Sediments from Equus Cave, Taung, Southern Kalahari (South Africa)

1987 ◽  
Vol 28 (1) ◽  
pp. 144-156 ◽  
Author(s):  
Louis Scott
Keyword(s):  
South Africa ◽  
Late Pleistocene ◽  
Pollen Analysis ◽  
Late Holocene ◽  
Climatic Conditions ◽  
Optimal Temperature ◽  
Local Sources ◽  
Moisture Conditions

AbstractEquus Cave, in Quaternary tufa near Taung in the semiarid woodland of the southern Kalahari, yielded 2.5 m of sediment in which a rich assemblage of bones and coprolites was preserved. The fossils were accumulated mainly by hyenas during the late Pleistocene and Holocene. Pollen from coprolites reflects diet as well as vegetation over relatively large areas visited by hyenas, while pollen from sediments represents more local sources. The pollen sequence derived from coprolites and sediments demonstrates how the vegetation evolved from open grassland with small shrubs and occasional trees during the late Pleistocene, to open savanna with more small shurbs, then, during the last 7500 yr, to modern savanna. Temperatures were not more than 4°C cooler and it was slightly moister than today during the late Pleistocene phase; it became gradually warmer but relatively dry before optimal temperature and moisture conditions developed around 7500 yr B.P. Climatic conditions slightly less favorable for woodland occurred during part of the late Holocene.

scholarly journals The role of selection in the evolution of marine turtles mitogenomes

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Elisa Karen da Silva Ramos ◽  
Lucas Freitas ◽  
Mariana F. Nery
Keyword(s):  
Oxidative Phosphorylation ◽  
Positive Selection ◽  
Adaptive Evolution ◽  
Sea Turtles ◽  
Mitochondrial Protein ◽  
Strong Support ◽  
Sea Turtle ◽  
Protein Coding ◽  
Codon Positions

Abstract Sea turtles are the only extant chelonian representatives that inhabit the marine environment. One key to successful colonization of this habitat is the adaptation to different energetic demands. Such energetic requirement is intrinsically related to the mitochondrial ability to generate energy through oxidative phosphorylation (OXPHOS) process. Here, we estimated Testudines phylogenetic relationships from 90 complete chelonian mitochondrial genomes and tested the adaptive evolution of 13 mitochondrial protein-coding genes of sea turtles to determine how natural selection shaped mitochondrial genes of the Chelonioidea clade. Complete mitogenomes showed strong support and resolution, differing at the position of the Chelonioidea clade in comparison to the turtle phylogeny based on nuclear genomic data. Codon models retrieved a relatively increased dN/dS (ω) on three OXPHOS genes for sea turtle lineages. Also, we found evidence of positive selection on at least three codon positions, encoded by NADH dehydrogenase genes (ND4 and ND5). The accelerated evolutionary rates found for sea turtles on COX2, ND1 and CYTB and the molecular footprints of positive selection found on ND4 and ND5 genes may be related to mitochondrial molecular adaptation to stress likely resulted from a more active lifestyle in sea turtles. Our study provides insight into the adaptive evolution of the mtDNA genome in sea turtles and its implications for the molecular mechanism of oxidative phosphorylation.

Wavelength Preferences and Brightness Cues in the Water Finding Behaviour of Sea Turtles

Behaviour ◽  
1968 ◽  
Vol 32 (4) ◽  
pp. 211-257 ◽  
Author(s):  
N. Osovsky ◽  
Sara J. Shettleworth
Keyword(s):  
Sea Turtles ◽  
Weather Conditions ◽  
Chelonia Mydas ◽  
Underlying Mechanism ◽  
Sea Turtle ◽  
Wide Field ◽  
Freshwater Turtles ◽  
Arena Test ◽  
Sensitivity Data ◽  
Open Horizon

AbstractExperiments with 1116 hatchling green sea turtles, Chelonia mydas, involving 1927 trials, revealed that 1. In preference tests between a blue and a red stimulus, or between a yellow and a red stimulus, the attractiveness of the red stimulus could be boosted by increasing its intensity relative to the blue or yellow alternative. Although there was a preference for a blue stimulus over a red containing equal energy, this preference could be reversed if the relative intensity of the red was made sufficiently high. 2. Pure blue or green lights did not attract turtles significantly more than blue/red or green/red mixtures containing greater amounts of energy. 3. When large visual obstructions were introduced into the natural beachscape hatchlings headed toward the centre of an open horizon. 4. Unilaterally blindfolded turtles circled toward the uncovered eye. In the present tests there was some directional progress along the shore. 5. Weather conditions could affect orientation; the influence of a freak cloud over the ocean horizon was described as an example. 6. Hatchlings had individual directional biases. Mildly aberrant animals that headed off at a slight angle to the surf during seafinding tended to show the same behaviour when retested. 7. The reaction to photic stimuli became weak in animals taken from environments above about 24° C. 8. The method of releasing animals in the turtle arena test did not greatly alter eseaward orientation (Appendix). The following interpretations are put on these results: The preference for a blue stimulus over a red depends partly on brightness. There could be a subsidiary colour preference for blues, since the red stimuli had to contain relatively more energy to make them behaviourally as potent as the blue or yellow than would have been expected on the basis of the ERG sensitivity data, and since in the mixing experiments there was no tendency to select the brighter stimuli. But if there is a blue preference the part it plays in seafinding can only be secondary compared to brightness. Simultaneous comparison of brightness cues from a wide field of view enables the turtle to head for the centre of an open horizon. The underlying mechanism involves a balancing of brightness inputs in both eyes. The hatchling orientates to maintain such a balance. Individual directional tendencies may be explained in terms of initial biases system; for instance, mild unilateral pathology leading to reduced sensitivity in one eye might be implicated. A number of other miscellaneous points and observations about water finding behaviour can be understood in terms of a balancing of brightness inputs, but there are a few cases in the literature of breakdown in seafinding that remain unexplained. The water finding of freshwater turtles probably requires other or auxiliary mechanisms. For the green sea turtle on the Tortuguero beaches the most open horizon is nearly always seaward and is nearly always brighter than the landward direction. These turtles have a brightness preference and a tropotactic reaction to light. Therefore the principal cue in their seafinding is the bright illumination from an open horizon.

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