scholarly journals Sacrum morphology supports taxonomic heterogeneity of Australopithecus africanus at Sterkfontein Member 4

2020 ◽  
Author(s):  
Cinzia Fornai ◽  
Viktoria Krenn ◽  
Philipp Mitteröcker ◽  
Nicole Webb ◽  
Martin Haeusler

Abstract The presence of multiple Australopithecus species at Sterkfontein Member 4, South Africa (2.07 to 2.61 Ma) is highly contentious. Quantitative assessments of craniodental and postcranial variability remain inconclusive. Using geometric morphometrics, we compared the sacrum of the small-bodied, presumed female subadult Australopithecus africanus skeleton Sts 14 and the large, alleged male adult StW 431 against a geographically diverse sample of modern humans, and two species for each of the genera Gorilla, Pan and Pongo. The probabilities of sampling morphologies as distinct as Sts 14 and StW 431 from a single species ranged from 1.3 to 2.5% for the human sample, and from 0.0 to 4.5% for the ape sample, depending on the analysis performed. Neither differences in developmental or geologic age nor sexual dimorphism could account for the differences between StW 431 and Sts 14 sacra. These findings support earlier claims of taxonomic heterogeneity at Sterkfontein Member 4.

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Cinzia Fornai ◽  
Viktoria A. Krenn ◽  
Philipp Mitteroecker ◽  
Nicole M. Webb ◽  
Martin Haeusler

AbstractThe presence of multiple Australopithecus species at Sterkfontein Member 4, South Africa (2.07–2.61 Ma), is highly contentious, and quantitative assessments of craniodental and postcranial variability remain inconclusive. Using geometric morphometrics, we compared the sacrum of the small-bodied, presumed female subadult Australopithecus africanus skeleton Sts 14 to the large, alleged male adult StW 431 against a geographically diverse sample of modern humans, and two species of Pan, Gorilla, and Pongo. The probabilities of sampling morphologies as distinct as Sts 14 and StW 431 from a single species ranged from 1.3 to 2.5% for the human sample, and from 0.0 to 4.5% for the great apes, depending on the species and the analysis. Sexual dimorphism and developmental or geologic age could not adequately explain the differences between StW 431 and Sts 14, suggesting that they are unlikely to be conspecific. This supports earlier claims of taxonomic heterogeneity at Sterkfontein Member 4.


Koedoe ◽  
2006 ◽  
Vol 49 (2) ◽  
Author(s):  
C.R. Haddad ◽  
A.S. Dippenaar-Schoeman ◽  
W. Wesołowska

Arachnids (Chelicerata: Arachnida) were collected in the Ndumo Game Reserve (Maputaland, South Africa) during 11 collecting trips in the period 2000–2006. Sampling was undertaken by various methods in eight broad habitat types: Acacia tortilis savanna; Acacia xanthophloea (fever tree) forests; deciduous broadleaf woodland; Ficus (wild fig tree) forests; floodplain vegetation; riparian forest; sand forest; and subtropical bush. In total, 457 species of arachnids were collected, representing six orders, 59 families and 240 determined genera. The most diverse order was the Araneae (46 families, 431 spp.), followed by the Pseudoscorpiones (6 families, 12 spp.), Scorpiones (3 families, 8 spp.), Opiliones (2 families, 3 spp.), Solifugae (1 family, 2 spp.) and Amblypygi (a single species). The most diverse families all belonged to the Araneae: Salticidae (82 spp.), Thomisidae (56 spp.) and Araneidae (38 spp.). The spider diversity is the highest recorded from any protected area in South Africa so far, and represents approximately 22 % of the country’s spider fauna. The habitat and guild associations of each species are provided.


Koedoe ◽  
1999 ◽  
Vol 42 (1) ◽  
Author(s):  
Anna S. Dippenaar-Schoeman ◽  
Astri Leroy ◽  
Marie De Jager ◽  
Annette Van den Berg

A check list of the spider species of the Karoo National Park collected over a period of 10 years is presented. Thirty-eight families, represented by 102 genera and 116 species have been collected. Of these species, 76 (66.4 ) were wanderers and 39 (33.6 ) web builders. The Araneidae have the highest number of species (14) followed by the Thomisidae (10) and the Gnaphosidae (8), while 14 families are represented by a single species. Information on spider guilds, their habitat preference and web types is provided. This study forms part of the South African National Survey of Arachnida (SANSA).


2021 ◽  
Vol 11 (17) ◽  
pp. 7848
Author(s):  
Darío Herranz-Rodrigo ◽  
Silvia J. Tardáguila-Giacomozzi ◽  
Lloyd A. Courtenay ◽  
Juan-José Rodríguez-Alba ◽  
Antonio Garrucho ◽  
...  

Recent studies using geometric morphometrics for taphonomy have yielded interesting results, opening new horizons of research in both archaeological and paleontological sites. Here we present the analysis of tooth pits left by male and female individuals of two different carnivore species (Panthera tigris and Panthera pardus) in order to see if sexual dimorphism influences the morphology of tooth pit marks. In the process, 3D-scanning and applied statistics were used. Based on samples derived from two individuals of different sexes, the present results indicate sexual dimorphism in these felid species to not be a conditioning factor of tooth pit morphology.


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7240 ◽  
Author(s):  
Kimberley E.J. Chapelle ◽  
Paul M. Barrett ◽  
Jennifer Botha ◽  
Jonah N. Choiniere

Our knowledge of Early Jurassic palaeobiodiversity in the upper Elliot Formation of South Africa has increased markedly in recent years with the discovery of new fossils, re-assessments of previously collected material and a better understanding of Stormberg Group stratigraphy. Here, Ngwevu intloko, a new genus of upper Elliot basal sauropodomorph is named on the basis of a complete skull and partial skeleton (BP/1/4779) previously assigned to Massospondylus carinatus. It can be distinguished from all other basal sauropodomorphs by a combination of 16 cranial and six postcranial characters. The new species is compared to a small ontogenetic series of M. carinatus as well as to a range of closely related taxa. Taphonomic deformation, sexual dimorphism and ontogeny are rejected as possible explanations for the morphological differences present between BP/1/4779 and other taxa. Osteohistological examination reveals that BP/1/4779 had nearly reached adult size at the time of its death at a minimum age of 10 years.


2021 ◽  
Vol 9 ◽  
Author(s):  
Daniel Martin ◽  
Chiara Romano

To date, the genus Amphiduros (Annelida: Hesionidae: Amphidurine) is considered as monotypic. Its single species, Amphiduros fuscescens (Marenzeller, 1875), is well characterised by lacking proboscideal papillae and emerging acicular chaetae, as well as by having three antennae, eight pairs of tentacular cirri and inflated dorsal cirri with characteristic alternating length and colour (transparent, with median orange band and white tips) in live animals. Three specimens, one male and two females, were found below boulders at 5–7 m depth in Punta Santa Anna, Blanes and Cala Maset, Sant Feliu de Guixols (Catalan Sea, NW Mediterranean, Iberian Peninsula). Our finding allowed us to describe different, unreported morphological traits and lead us to support the existence of sexual dimorphism (in terms of colouring, cirri morphology and distribution of sexual products along the body). Despite A. fuscescens having been previously reported from the Atlantic and the Mediterranean (particularly in SE French coasts), the specimens from Blanes represent the first record of the species from the Iberian Peninsula. In addition, our molecular results strongly support that Amphiduros pacificus Hartman, 1961 from California (currently synonymised with A. fuscescens) requires to be re-described and reinstalled as a valid species. In turn, our morphological observations support suggesting all other non-Mediterranean reports of A. fuscescens, including the species still under synonymy (i.e. Amphidrornus izukai Hessle, 1925 and Amphidromus setosus Hessle, 1925) as likely being a cryptic species complex whose the taxonomic status requires further assessment.


Author(s):  
Rainer Kühne

I argue that the evidence of the Out-of-Africa hypothesis and the evidence of multiregional evolution of prehistorical humans can be understood if there has been interbreeding between Homo erectus, Homo neanderthalensis, and Homo sapiens at least during the preceding 700,000 years. These interbreedings require descendants who are capable of reproduction and therefore parents who belong to the same species. I suggest that a number of prehistorical humans who are at present regarded as belonging to different species belong in fact to one single species.  


1991 ◽  
Vol 23 (1-3) ◽  
pp. 175-180 ◽  
Author(s):  
W. E. Scott

A comprehensive list is provided of more than forty cyanobacterial species and genera reported to have toxic properties. In South Africa the majority of animal poisonings since 1927 have been caused by a single species Microcystis aeruginosa. Although other toxic species also occur in southern Africa, to date they have been of little practical significance. The widespread distribution of M. aeruginosa throughout southern Africa indicates a tremendous potential for toxic blooms to develop with increasing eutrophication. Using HPLC techniques up to six different toxin variants have been quantified in natural blooms of M. aeruginosa collected in different parts of South Africa. The amounts and proportions of the different toxins in the different samples varied over a wide range. Several additional unidentified toxins were detected.


2020 ◽  
Vol 117 (15) ◽  
pp. 8416-8423 ◽  
Author(s):  
Leoni Georgiou ◽  
Christopher J. Dunmore ◽  
Ameline Bardo ◽  
Laura T. Buck ◽  
Jean-Jacques Hublin ◽  
...  

Bipedalism is a defining trait of the hominin lineage, associated with a transition from a more arboreal to a more terrestrial environment. While there is debate about when modern human-like bipedalism first appeared in hominins, all known South African hominins show morphological adaptations to bipedalism, suggesting that this was their predominant mode of locomotion. Here we present evidence that hominins preserved in the Sterkfontein Caves practiced two different locomotor repertoires. The trabecular structure of a proximal femur (StW 522) attributed to Australopithecus africanus exhibits a modern human-like bipedal locomotor pattern, while that of a geologically younger specimen (StW 311) attributed to either Homo sp. or Paranthropus robustus exhibits a pattern more similar to nonhuman apes, potentially suggesting regular bouts of both climbing and terrestrial bipedalism. Our results demonstrate distinct morphological differences, linked to behavioral differences between Australopithecus and later hominins in South Africa and contribute to the increasing evidence of locomotor diversity within the hominin clade.


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