Pub Date : 2022-01-02DOI: 10.1080/0035919X.2021.2005716
J. Hey
The elementary application of complex variable theory in an earlier paper [Hey, J.D. 2020. On elementary complex variable theory applied to sinc and related integrals. Transactions of the Royal Society of South Africa 75(3): 295–306] is extended by use of the generalised sinc(p) function defined below, in order to provide some interesting, additional insight into the behaviour of the Borwein integrals, which arise as simple consequences of Jordan’s lemma applied to Cauchy’s theorem. The present treatment is of physical interest in relation to the analysis of spectral line broadening by the electric fields of ion perturbers in laboratory and astrophysical plasmas. Finally, a result, stated as a student problem in the well-known treatise [Whittaker, E.T. & Watson, G.N. 1927. A Course of Modern Analysis, Ch. VI (4th ed.). Cambridge University Press], is formulated in more general terms with the aid of the sinc(p) function. The simplicity of application of the present analytical results is extensively illustrated by numerical tables.
{"title":"On elementary complex variable theory applied to generalised sinc(p) and related integrals","authors":"J. Hey","doi":"10.1080/0035919X.2021.2005716","DOIUrl":"https://doi.org/10.1080/0035919X.2021.2005716","url":null,"abstract":"The elementary application of complex variable theory in an earlier paper [Hey, J.D. 2020. On elementary complex variable theory applied to sinc and related integrals. Transactions of the Royal Society of South Africa 75(3): 295–306] is extended by use of the generalised sinc(p) function defined below, in order to provide some interesting, additional insight into the behaviour of the Borwein integrals, which arise as simple consequences of Jordan’s lemma applied to Cauchy’s theorem. The present treatment is of physical interest in relation to the analysis of spectral line broadening by the electric fields of ion perturbers in laboratory and astrophysical plasmas. Finally, a result, stated as a student problem in the well-known treatise [Whittaker, E.T. & Watson, G.N. 1927. A Course of Modern Analysis, Ch. VI (4th ed.). Cambridge University Press], is formulated in more general terms with the aid of the sinc(p) function. The simplicity of application of the present analytical results is extensively illustrated by numerical tables.","PeriodicalId":23255,"journal":{"name":"Transactions of The Royal Society of South Africa","volume":"77 1","pages":"11 - 25"},"PeriodicalIF":0.0,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44571754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-02DOI: 10.1080/0035919X.2021.2004470
S. Jombo, E. Adam, M. Byrne, S. W. Newete
Urban trees play a critical role in alleviating land surface temperatures in cities. In remote sensing studies, vegetation indices are widely used to examine the relationship between Land Surface Temperature (LST) and vegetation cover. The vegetation cover can be measured using the Normalised Difference Vegetation Index (NDVI). In this study, the LST-NDVI relationship was assessed in each of the seven city-regions (A-G) in Johannesburg using Moderate-Resolution Imaging Spectroradiometer (MODIS) datasets to provide a basis for urban ecological planning and environmental protection. This study's specific objective was to determine the intraurban differences in vegetation coverage and LST in the seven city-regions over 19 years. The relationship between LST and NDVI was also examined over the years of study. The results showed a significant intraurban difference in LST and NDVI values in the city-regions with a negative correlation between them, ranging from −0.03 to −0.76. The LST values increased in all the city-regions with the highest value of 20.1°C in city-region G, followed by 19.6°C in city-region E. The vegetation cover decreased over the years, with the lowest NDVI value in city-region G (0.39), followed by city-regions F (0.43) and D (0.48). The city-regions with high LST and low vegetation cover include the city-centre and highly populated suburbs. This indicates that areas with greater vegetation cover have low LSTs and vice versa. These findings provide useful information for municipal authorities and other stakeholders to undertake appropriate decisions to tackle Urban Heat Island (UHI) effects by adopting effective urban planning and management interventions.
{"title":"Assessing the intraurban differences in vegetation coverage and surface climate in a heterogeneous area","authors":"S. Jombo, E. Adam, M. Byrne, S. W. Newete","doi":"10.1080/0035919X.2021.2004470","DOIUrl":"https://doi.org/10.1080/0035919X.2021.2004470","url":null,"abstract":"Urban trees play a critical role in alleviating land surface temperatures in cities. In remote sensing studies, vegetation indices are widely used to examine the relationship between Land Surface Temperature (LST) and vegetation cover. The vegetation cover can be measured using the Normalised Difference Vegetation Index (NDVI). In this study, the LST-NDVI relationship was assessed in each of the seven city-regions (A-G) in Johannesburg using Moderate-Resolution Imaging Spectroradiometer (MODIS) datasets to provide a basis for urban ecological planning and environmental protection. This study's specific objective was to determine the intraurban differences in vegetation coverage and LST in the seven city-regions over 19 years. The relationship between LST and NDVI was also examined over the years of study. The results showed a significant intraurban difference in LST and NDVI values in the city-regions with a negative correlation between them, ranging from −0.03 to −0.76. The LST values increased in all the city-regions with the highest value of 20.1°C in city-region G, followed by 19.6°C in city-region E. The vegetation cover decreased over the years, with the lowest NDVI value in city-region G (0.39), followed by city-regions F (0.43) and D (0.48). The city-regions with high LST and low vegetation cover include the city-centre and highly populated suburbs. This indicates that areas with greater vegetation cover have low LSTs and vice versa. These findings provide useful information for municipal authorities and other stakeholders to undertake appropriate decisions to tackle Urban Heat Island (UHI) effects by adopting effective urban planning and management interventions.","PeriodicalId":23255,"journal":{"name":"Transactions of The Royal Society of South Africa","volume":"77 1","pages":"1 - 10"},"PeriodicalIF":0.0,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41392785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-02DOI: 10.1080/0035919X.2022.2036265
S. S. Sobowale, O. Olatidoye, Idowu Atinuke, O. Emeka
The major drawback of most starchy food is its inability to withstand high-temperature conditions, shearing force and acidity, which limits its usage in the food industry. This study investigates the effect of heat-moisture treatment (HMT) at varying moisture content (10–30% wet basis), drying temperature (80–100 °C) and time (2–8 h) on the functional and rheological properties of cassava starch using response surface methodology (RSM) by adopting a Box–Behnken design method. Cassava roots were processed into modified starch under various processing conditions. Results showed an increase in the water absorption index, solubility and swelling power while there was a slight reduction in the loose bulk density and tapped bulk density. The starch viscosity ranged between 4182 and 4268 Cps. Consistency ranged between 2.51 and 2.56 g/mL and the flow behaviour index ranged between 2.70 and 2.82. Optimal processing conditions for cassava starch were achieved with a moisture content of 30%, drying temperature of 90 °C and time of 2 h. These variables are important to consider for processing of cassava starch with improved consumer acceptability and potential large-scale production of baked foods, gel formation and custard production.
{"title":"Effect of heat-moisture treatment on the functional and rheological characteristics of cassava (Manihot esculenta) starch","authors":"S. S. Sobowale, O. Olatidoye, Idowu Atinuke, O. Emeka","doi":"10.1080/0035919X.2022.2036265","DOIUrl":"https://doi.org/10.1080/0035919X.2022.2036265","url":null,"abstract":"The major drawback of most starchy food is its inability to withstand high-temperature conditions, shearing force and acidity, which limits its usage in the food industry. This study investigates the effect of heat-moisture treatment (HMT) at varying moisture content (10–30% wet basis), drying temperature (80–100 °C) and time (2–8 h) on the functional and rheological properties of cassava starch using response surface methodology (RSM) by adopting a Box–Behnken design method. Cassava roots were processed into modified starch under various processing conditions. Results showed an increase in the water absorption index, solubility and swelling power while there was a slight reduction in the loose bulk density and tapped bulk density. The starch viscosity ranged between 4182 and 4268 Cps. Consistency ranged between 2.51 and 2.56 g/mL and the flow behaviour index ranged between 2.70 and 2.82. Optimal processing conditions for cassava starch were achieved with a moisture content of 30%, drying temperature of 90 °C and time of 2 h. These variables are important to consider for processing of cassava starch with improved consumer acceptability and potential large-scale production of baked foods, gel formation and custard production.","PeriodicalId":23255,"journal":{"name":"Transactions of The Royal Society of South Africa","volume":"77 1","pages":"89 - 99"},"PeriodicalIF":0.0,"publicationDate":"2022-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44450978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-16DOI: 10.1080/0035919X.2021.2011801
S. A. Abdool Karim, C. Baxter
The Covid-19 pandemic has resulted in immense suffering throughout the world, with over 250 million cases and over 5 million Covid-19-related deaths reported by 9 November 2021. South Africa has the highest burden of Covid-19 in Africa, accounting for 34% of all cases and 41% of all reported Covid-19 deaths on the continent (Africa CDC COVID-19 Dashboard, 2021). By 1 November 2021, South Africa had reported more than 2.9 million Covid-19 cases and over 89,000 Covid-19 deaths (COVID-19 Corona Virus South African Resource Portal, 2020), with substantial cases and deaths due to the Beta variant in the second wave and to the Delta variant in the third wave. Given the importance of variants in determining what the waves of infection look like, the future trajectory of the SARS-CoV-2 epidemic in South Africa will be largely dependent on viral variants. The fi rst case of Covid-19 in South Africa was reported on 5 March 2020 by a traveller who had recently returned from Italy. Although mitigation measures, such as a national lock-down and border closures, initially kept Covid-19 cases low, there was a steady increase in cases as restrictions eased. In the fi rst wave, the average daily Covid-19 cases peaked at 12,583 in mid-July 2020, driven principally by variants with the D614G mutation. The second wave began in late November 2020 and the average daily Covid-19 cases peaked at 19,042 in January 2021. By mid-May 2021, the country once again began experiencing a surge in cases, reaching a peak of 19,958 in July 2021 in the country ’ s
{"title":"Impact of SARS-CoV-2 variants of concern on Covid-19 epidemic in South Africa","authors":"S. A. Abdool Karim, C. Baxter","doi":"10.1080/0035919X.2021.2011801","DOIUrl":"https://doi.org/10.1080/0035919X.2021.2011801","url":null,"abstract":"The Covid-19 pandemic has resulted in immense suffering throughout the world, with over 250 million cases and over 5 million Covid-19-related deaths reported by 9 November 2021. South Africa has the highest burden of Covid-19 in Africa, accounting for 34% of all cases and 41% of all reported Covid-19 deaths on the continent (Africa CDC COVID-19 Dashboard, 2021). By 1 November 2021, South Africa had reported more than 2.9 million Covid-19 cases and over 89,000 Covid-19 deaths (COVID-19 Corona Virus South African Resource Portal, 2020), with substantial cases and deaths due to the Beta variant in the second wave and to the Delta variant in the third wave. Given the importance of variants in determining what the waves of infection look like, the future trajectory of the SARS-CoV-2 epidemic in South Africa will be largely dependent on viral variants. The fi rst case of Covid-19 in South Africa was reported on 5 March 2020 by a traveller who had recently returned from Italy. Although mitigation measures, such as a national lock-down and border closures, initially kept Covid-19 cases low, there was a steady increase in cases as restrictions eased. In the fi rst wave, the average daily Covid-19 cases peaked at 12,583 in mid-July 2020, driven principally by variants with the D614G mutation. The second wave began in late November 2020 and the average daily Covid-19 cases peaked at 19,042 in January 2021. By mid-May 2021, the country once again began experiencing a surge in cases, reaching a peak of 19,958 in July 2021 in the country ’ s","PeriodicalId":23255,"journal":{"name":"Transactions of The Royal Society of South Africa","volume":"77 1","pages":"101 - 104"},"PeriodicalIF":0.0,"publicationDate":"2021-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46579588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-02DOI: 10.1080/0035919X.2021.1969797
M. Bruton
{"title":"Biological invasions in South Africa","authors":"M. Bruton","doi":"10.1080/0035919X.2021.1969797","DOIUrl":"https://doi.org/10.1080/0035919X.2021.1969797","url":null,"abstract":"","PeriodicalId":23255,"journal":{"name":"Transactions of The Royal Society of South Africa","volume":"76 1","pages":"301 - 305"},"PeriodicalIF":0.0,"publicationDate":"2021-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42222518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-02DOI: 10.1080/0035919x.2021.1976497
S. A. Craven
{"title":"Obituary: Peter Ernest Spargo (07 June 1937–02 Aug. 2021)","authors":"S. A. Craven","doi":"10.1080/0035919x.2021.1976497","DOIUrl":"https://doi.org/10.1080/0035919x.2021.1976497","url":null,"abstract":"","PeriodicalId":23255,"journal":{"name":"Transactions of The Royal Society of South Africa","volume":"76 1","pages":"309 - 309"},"PeriodicalIF":0.0,"publicationDate":"2021-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48707121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-02DOI: 10.1080/0035919x.2021.1983325
C. Anhaeusser
{"title":"Morris James Viljoen (1940–2021)","authors":"C. Anhaeusser","doi":"10.1080/0035919x.2021.1983325","DOIUrl":"https://doi.org/10.1080/0035919x.2021.1983325","url":null,"abstract":"","PeriodicalId":23255,"journal":{"name":"Transactions of The Royal Society of South Africa","volume":"76 1","pages":"311 - 312"},"PeriodicalIF":0.0,"publicationDate":"2021-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47990133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-02DOI: 10.1080/0035919X.2021.1982792
D. Coertzen, J. Reader, Mariëtte E. van der Watt, Meta Leshabane, Henrico Langeveld, P. Cheuka, G. Dziwornu, K. Chibale, L. Birkholtz
The effectiveness of current antimalarial therapies that cure patients of the pathogenic asexual blood stages is rapidly declining due to the spread of antimalarial drug resistance. This requires the development of novel chemotypes curative for asexual blood stages but additionally, such chemotypes should also target the sexually differentiated gametocytes and thereby block disease transmission. Kinase inhibitors, specifically imidazopyridazines, were previously described as highly effective, dual-active compounds in vitro. However, amongst other shortcomings, poor solubility and cardiotoxicity risks prevented these compounds from being further developed. In a recent study, novel 3,6-diarylated imidazopyridazine derivatives showed improved solubility and a decrease in inhibition of the human ether-a-go-go-related gene (hERG), suggesting reduced cardiotoxicity risks, with potent sub-micromolar antiplasmodial activities. Here, we report the in vitro activity of these 3,6-diarylated imidazopyridazine derivates against both asexual blood and gametocyte stages of the human malaria parasite, Plasmodium falciparum, in vitro. We highlight several potentially dual-active compounds with nanomolar activities (IC50’s 0.7–104 nM) against both drug sensitive and resistant strains of P. falciparum with these compounds also displaying activity against transmissible gametocytes (IC50’s 1180.3–1787.5 nM). Taken together, the new generation 3,6-diarylated imidazopyridazines have potent activity against P. falciparum parasites in vitro with improved physicochemical and toxicity profiles.
{"title":"Exploring the transmission-blocking activity of antiplasmodial 3,6-diarylated imidazopyridazines","authors":"D. Coertzen, J. Reader, Mariëtte E. van der Watt, Meta Leshabane, Henrico Langeveld, P. Cheuka, G. Dziwornu, K. Chibale, L. Birkholtz","doi":"10.1080/0035919X.2021.1982792","DOIUrl":"https://doi.org/10.1080/0035919X.2021.1982792","url":null,"abstract":"The effectiveness of current antimalarial therapies that cure patients of the pathogenic asexual blood stages is rapidly declining due to the spread of antimalarial drug resistance. This requires the development of novel chemotypes curative for asexual blood stages but additionally, such chemotypes should also target the sexually differentiated gametocytes and thereby block disease transmission. Kinase inhibitors, specifically imidazopyridazines, were previously described as highly effective, dual-active compounds in vitro. However, amongst other shortcomings, poor solubility and cardiotoxicity risks prevented these compounds from being further developed. In a recent study, novel 3,6-diarylated imidazopyridazine derivatives showed improved solubility and a decrease in inhibition of the human ether-a-go-go-related gene (hERG), suggesting reduced cardiotoxicity risks, with potent sub-micromolar antiplasmodial activities. Here, we report the in vitro activity of these 3,6-diarylated imidazopyridazine derivates against both asexual blood and gametocyte stages of the human malaria parasite, Plasmodium falciparum, in vitro. We highlight several potentially dual-active compounds with nanomolar activities (IC50’s 0.7–104 nM) against both drug sensitive and resistant strains of P. falciparum with these compounds also displaying activity against transmissible gametocytes (IC50’s 1180.3–1787.5 nM). Taken together, the new generation 3,6-diarylated imidazopyridazines have potent activity against P. falciparum parasites in vitro with improved physicochemical and toxicity profiles.","PeriodicalId":23255,"journal":{"name":"Transactions of The Royal Society of South Africa","volume":"76 1","pages":"225 - 233"},"PeriodicalIF":0.0,"publicationDate":"2021-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48335374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-02DOI: 10.1080/0035919X.2021.1995530
V. Ramborun, S. Facknath, B. Lalljee
The study seeks to investigate the compounding effects of various practices such as mulch, no-tillage, tillage and nitrogen based fertilizer on CO2 emission and soil organic carbon (SOC) in three successive crop cycles in the region of Vacoas, Mauritius. Nitrogen based fertilizer (ammonium sulphate) was applied at 120 kg/ha to its corresponding treatment, and maize mulch was applied as full coverage (24 t/ha). Three treatments: Mulch (M), Fertilizer (F), Tillage (T), were tested at 2 levels each, and replicated 3 times. The 2 levels were mulch-no mulch, fertilizer-no fertilizer and tillage-no tillage. Results have shown a correlation between CO2 and pH, where increase in CO2 flux was due to addition of fertilizer. Furthermore, application of mulch did not increase SOC in the short term. A negative correlation was equally found between available phosphorous and temperature which was attributed to the interactions that exist between temperature, photosynthesis and nutrient availability. The present study revealed that reduction in CO2 emission and increase in soil fertility can be achieved at farmer level by adopting mulching and no-till. These practices are both economical and farmer friendly. This is a first study of such kind in the soils of Mauritius, a volcanic Island in the Indian Ocean latitude 20° 17′ 53″ South and longitude 57° 28′ 42″ East.
{"title":"Effect of mulch, no-tillage and no-fertiliser as sustainable practices on soil organic carbon and carbon dioxide emission","authors":"V. Ramborun, S. Facknath, B. Lalljee","doi":"10.1080/0035919X.2021.1995530","DOIUrl":"https://doi.org/10.1080/0035919X.2021.1995530","url":null,"abstract":"The study seeks to investigate the compounding effects of various practices such as mulch, no-tillage, tillage and nitrogen based fertilizer on CO2 emission and soil organic carbon (SOC) in three successive crop cycles in the region of Vacoas, Mauritius. Nitrogen based fertilizer (ammonium sulphate) was applied at 120 kg/ha to its corresponding treatment, and maize mulch was applied as full coverage (24 t/ha). Three treatments: Mulch (M), Fertilizer (F), Tillage (T), were tested at 2 levels each, and replicated 3 times. The 2 levels were mulch-no mulch, fertilizer-no fertilizer and tillage-no tillage. Results have shown a correlation between CO2 and pH, where increase in CO2 flux was due to addition of fertilizer. Furthermore, application of mulch did not increase SOC in the short term. A negative correlation was equally found between available phosphorous and temperature which was attributed to the interactions that exist between temperature, photosynthesis and nutrient availability. The present study revealed that reduction in CO2 emission and increase in soil fertility can be achieved at farmer level by adopting mulching and no-till. These practices are both economical and farmer friendly. This is a first study of such kind in the soils of Mauritius, a volcanic Island in the Indian Ocean latitude 20° 17′ 53″ South and longitude 57° 28′ 42″ East.","PeriodicalId":23255,"journal":{"name":"Transactions of The Royal Society of South Africa","volume":"76 1","pages":"247 - 255"},"PeriodicalIF":0.0,"publicationDate":"2021-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43095635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-30DOI: 10.1080/0035919X.2021.1964104
D. V. van Dijk, P. Eriksson
The Lower Jurassic Clarens Formation (Stormberg Group, Karoo Supergroup, Main Karoo basin) contains relatively common vertebrate trackways impressed into apparently soft to firm, fine sediment beds preserved within the succession. At least three known ichnotaxa are interpreted as leaping bipedal vertebrates. Here we provide a generic description of a proposed new ichnotaxon to add to this small group of the oldest known bipedal hopping vertebrates in Africa and globally. Saltirecarpipes Genus Nova (Type Species tinleyi) (saltus – leap; carpe – seize; pes – foot) has been identified from tracks at Giants Castle in the KwaZulu-Natal Drakensberg. The type specimen in the National Museum Bloemfontein exhibits two adjacent tetradactyl impressions with four digits extended from metatarsal pads, comprising three inner digits grouped closer together and facing forwards, the fourth digit being much longer and curved outwards and slightly backwards. The digits are all strongly curved with claw impressions being preserved in several cases. These were small vertebrates, a leap length of ca. 180 mm being inferred. Being found in association with trace fossils of Equisitales (horse tails) a wet palaeoenvironment of small ponds is postulated. These appear to have been associated with distal fan sheetflood deposits of fine sediment at Giants Castle, which pass laterally into more central-basinal palaeodune deposits which characterise the Clarens Formation across the Main Karoo depository. The new ichnotaxon appears to have been restricted to wet desert marginal settings, feeding immature sediment to the desert basin, and which retreated proximally as aridification of the Clarens palaeoenvironment progressed.
{"title":"Bipedal leaping Jurassic vertebrates in Southern Africa: proposed new ichnotaxon and inferred palaeoenvironment","authors":"D. V. van Dijk, P. Eriksson","doi":"10.1080/0035919X.2021.1964104","DOIUrl":"https://doi.org/10.1080/0035919X.2021.1964104","url":null,"abstract":"The Lower Jurassic Clarens Formation (Stormberg Group, Karoo Supergroup, Main Karoo basin) contains relatively common vertebrate trackways impressed into apparently soft to firm, fine sediment beds preserved within the succession. At least three known ichnotaxa are interpreted as leaping bipedal vertebrates. Here we provide a generic description of a proposed new ichnotaxon to add to this small group of the oldest known bipedal hopping vertebrates in Africa and globally. Saltirecarpipes Genus Nova (Type Species tinleyi) (saltus – leap; carpe – seize; pes – foot) has been identified from tracks at Giants Castle in the KwaZulu-Natal Drakensberg. The type specimen in the National Museum Bloemfontein exhibits two adjacent tetradactyl impressions with four digits extended from metatarsal pads, comprising three inner digits grouped closer together and facing forwards, the fourth digit being much longer and curved outwards and slightly backwards. The digits are all strongly curved with claw impressions being preserved in several cases. These were small vertebrates, a leap length of ca. 180 mm being inferred. Being found in association with trace fossils of Equisitales (horse tails) a wet palaeoenvironment of small ponds is postulated. These appear to have been associated with distal fan sheetflood deposits of fine sediment at Giants Castle, which pass laterally into more central-basinal palaeodune deposits which characterise the Clarens Formation across the Main Karoo depository. The new ichnotaxon appears to have been restricted to wet desert marginal settings, feeding immature sediment to the desert basin, and which retreated proximally as aridification of the Clarens palaeoenvironment progressed.","PeriodicalId":23255,"journal":{"name":"Transactions of The Royal Society of South Africa","volume":"76 1","pages":"235 - 245"},"PeriodicalIF":0.0,"publicationDate":"2021-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41464527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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