Robert Gess

Rhodes University | RU · Albany Museum

We describe the largest bony fish in the Late Devonian (late Famennian) fossil assemblage from Waterloo Farm near Makhanda/Grahamstown, South Africa. It is a giant member of the extinct clade Tristichopteridae (Sarcopterygii: Tetrapodomorpha) and most closely resembles Hyneria lindae from the late Famennian Catskill Formation of Pennsylvania, USA....

A formerly unknown fossil-bearing locality in the lower part of the Witpoort Formation (Witteberg Group, Cape Supergroup) is described from the Eastern Cape (South Africa). Uniquely for these strata, it provides evidence for a back-barrier lagoon hosting a monospecific lingulid brachiopod fauna. This represents the youngest record of marine inverte...

A new fossil plant, Flabellopteris lococannensis Gess and Prestianni gen. et sp. nov., is described from the Famennian of South Africa. This plant is interpreted as monopodial in habit with a first order axis that only occasionally dichotomizes. The lateral organs (both branches and appendages) are borne spirally on all branching orders and a 1/3 o...

This study defines a new bivalve species, Naiadites devonicus nov. sp., of Famennian (Late Devonian) age. The material was excavated from the non-marine deposits of the Waterloo Farm Lagerstätte in South Africa, which form part of the Witpoort Formation (Witteberg Group, Cape Supergroup) of the Cape Fold Belt region. The type material of Naiadites...

Newly discovered early plant bearing lenses from the Baviaanskloof Formation at Impofu Dam in the Eastern Cape Province of South Africa provide evidence for one of the most diverse Late Silurian to Early Devonian assemblages known to date. This work represents the first account of this flora. Fifteen taxa are presented, including eleven diagnosed t...

Localities within strata of the Witpoort Formation (Witteberg Group, Cape Supergroup) of South Africa provide diverse new fossil material of Famennian plants from a high paleolatitude marginal marine setting. Lycopsid axes with sterile leaves include material here diagnosed to two new species of Colpodexylon Banks 1944. C. pullumpedes sp. nov. from...

Coombs Hill, a new fossil locality in the Witpoort Formation (Witteberg Group) of South Africa, preserves a record of Famennian (Late Devonian) life in Gondwana. Fossil plants collected at Coombs Hill are preliminarily assigned to several classes. Shelly invertebrates include a variety of bivalve mollusc forms, some of which appear to be preserved...

Ammocoetes—the filter-feeding larvae of modern lampreys—have long influenced hypotheses of vertebrate ancestry1–7. The life history of modern lampreys, which develop from a superficially amphioxus-like ammocoete to a specialized predatory adult, appears to recapitulate widely accepted scenarios of vertebrate origin. However, no direct evidence has...

The Waterloo Farm lagerstätte in South Africa provides a uniquely well‐preserved record of a Latest Devonian estuarine ecosystem. Ecological evidence from it is reviewed, contextualised, and compared with that available from the analogous Swartvlei estuarine lake, with a particular emphasis on their piscean inhabitants. Although the taxonomic affin...

New fossil lungfish remains comprising two parasphenoids, tooth plates and scales from the Famennian Witpoort Formation of South Africa are described. From the parasphenoid material, which bears similarity to Oervigia and Sagenodus but is nevertheless unique, a new genus, Isityumzi mlomomde gen. et sp. nov. is erected. Tooth plates and scales from...

We present a comprehensive qualitative and quantitative study of the manus of a new therocephalian specimen referable to Tetracynodon from the Early Triassic of South Africa. We examined 18 specimens, representing at least 12 genera, including basal therocephalians (Lycosuchidae and Scylacosauridae) and eutherocephalians (Akidnognathidae, Whaitsioi...

A rich and diverse plant assemblage has been excavated from latest Devonian (Famennian) black shales of the Witpoort Formation (Witteberg Group) at Waterloo Farm, close to the city of Grahamstown (South Africa). Several specimens of a new sphenopsid have been collected. The description of this as a new taxon, here named Rinistachya hilleri, gen. et...

Extensive rock cuttings generated in 2015 and 2016 expose a number of fossiliferous shale strata interbedded in quartzites of the Upper Devonian Witpoort Formation (Witteberg Group, Cape Supergroup) on Governor's Kop, near Grahamstown. Intensive palaeontological sampling of the shale horizons recovered an array of Late Devonian fossil plants and in...

A laterally extensive organic rich mudstone horizon in the lower part of the Witpoort Formation, was sampled during road excavations. It preserves numerous lingulid brachiopod shells, distributed in patches over 3.5 km of outcrop. Both bedding-oblique (in-situ) and bedding parallel valves are concentrated in the upper part of the mudstone layer, wh...

Out of Antarctica When we think of Devonian tetrapods, the ancestors of all modern vertebrates, we tend to picture amphibian-like creatures emerging from the water into a wet tropical forest or swamp. Indeed, all previously described specimens of this group have been recovered from the tropics. Gess and Ahlberg now describe two fossil tetrapods fro...

A new lycopsid, Kowieria alveoformis gen. et sp. nov., is described from the Famennian Witpoort Formation, Gra-hamstown, South Africa. It possesses spirally arranged elongated falcate vegetative leaves. Terminal bisporangiate strobili are present and show loosely grouped micro-and megasporophylls. Sporophylls are similar in shape to the vegetative...

Here we present a new species of placoderm fish, Africanaspis edmountaini sp. nov., and redescribe Africanaspis doryssa on the basis of new material collected from the type locality of Africanaspis. The new material includes the first head shields of Africanaspis doryssa in addition to soft anatomy for both taxa. Hitherto Africanaspis was entirely...

A phased mass extinction event (which culminated in the Hangenberg event) marked the end of the Devonian period and had a significant impact on the palaeoecology and faunal diversity of vertebrate and invertebrate communities. In the present study the taxonomy of bivalves from the Waterloo Farm lagerst?tte of the Upper Devonian, Famennian, Witpoort...

Chimaeroid fishes (Holocephali) are one of the four principal divisions of modern gnathostomes (jawed vertebrates). Despite only 47 described living species, chimaeroids are the focus of resurgent interest as potential archives of genomic data and for the unique perspective they provide on chondrichthyan and gnathostome ancestral conditions. Chimae...

Witteberg Group rocks are Late Devonian to Early Carboniferous in age. Comparison with Laurasian sea-level curves has correlated the earliest Carboniferous Tournasian transgression, with the argillaceous Kweekvlei Formation, overlying the arenaceous Witpoort Formation. The Devonian/Carboniferous boundary is globally characterised by a Mass Extincti...

A new coelacanth genus from the Famennian (Upper Devonian) of South Africa is described, principally from presumed juveniles. Serenichthys kowiensis gen. et sp. nov. uniquely shares with Diplocercides a ventral expansion of the elbow-like lachrymojugal, as well as a symmetrical diphycercal tail supported by expanded neural and haemal spines and rad...

New material from the Late Devonian Witpoort Formation (Witteberg Group, Cape Supergroup) of Waterloo Farm (Grahamstown, South Africa) includes teeth, spines, and rare endoskeletal remains of early chondrichthyans. Plesioselachus, formerly described from Waterloo Farm, is redescribed and reinterpreted on the basis of new specimens. A new species of...

The new genus and species, Gondwanascorpio emzantsiensis, are described in Scorpiones incertae se dis on the basis of fragments from the Famennian (Late Devonian) Waterloo Farm locality near Grahams town, Eastern Cape, South Africa. This finding adds to the sparse record of Late Devonian scorpion taxa and pro-vides the first evidence of Palaeozoic...

  A new, third, specimen of Onychoselache traquairi from the Viséan (Holkerian) of Scotland allows a significant revision of the anatomy of this stem-group elasmobranch. This first report of material from the Mumbie Quarry exposure of the Glencartholm fish beds presents a new reconstruction of Onychoselache showing broad-based cephalic and nuchal s...

Lampreys are the most scientifically accessible of the remaining jawless vertebrates, but their evolutionary history is obscure. In contrast to the rich fossil record of armoured jawless fishes, all of which date from the Devonian period and earlier, only two Palaeozoic lampreys have been recorded, both from the Carboniferous period. In addition to...

New placoderm fishes are described from a black shale lens in the Famennian Witpoort Formation, near Grahamstown, South Africa. Arthrodires include a new species of Groenlandaspis, G. riniensis sp. nov., a new genus of groenlandaspidid, Africanaspis doryssa gen. et sp. nov., and a new species of the antiarch Bothriolepis, B. africana sp. nov. This...

The remains of what are interpreted to be marine brown algae are described from Late Devonian clastic rocks in South Africa. Dichotomously-branched specimens with rounded terminations are placed in the new species Hungerfordia fionae and the closely related H. dichotoma Fry and Banks is placed in synonymy with Buthotrephis trichotoma Douglas and Je...

The first record of Palaeozoic charophytes from southern Africa allows the establishment of two new genera to which are assigned four new species, Octochara crassa, O. gracilis, Hexachara setacea, and H. riniensis. Each species is represented by both vegetative and reproductive structures and suggested reconstructions are presented. Associated plan...

Archaeopteris notosaria sp. nov. based on one fertile and numerous sterile leafy branches is described from the Grahamstown By-Pass locality, Witpoort Formation (Witteberg Group) Upper Devonian, and represents the first unequivocal record of the genus in southern Africa. This occurrence is used, in its palaeogeographical context, to support the sug...

A black carbonaceous shale, exposed in road cuttings that intersected rocks of the Witpoort Formation, Eastern Cape Province, South Africa, has yielded the fragmentary remains of about 50 fishes, in addition to numerous plant fossils. The depositional site is interpreted to have been a stagnant coastal lagoon sheltered by a barrier island. The fish...