Hungerfordia Temporal range: | |
---|---|
Scientific classification | |
Kingdom: | Plantae |
Division: | incertae sedis |
Genus: | † Hungerfordia Fry and Banks, 1955 |
Type species | |
Hungerfordia dichotoma [1] Fry and Banks, 1955 |
Hungerfordia is a genus of presumed marine algae first described by Fry and Banks in 1955 in describing Hungerfordia dichotoma from Late Devonian strata. [2] It has been interpreted as a probable brown (Phaeophyte) algae [2] though the possibility that it represents a red (Rhodophyte) alga is not excluded [3] [4] - the taxonomic challenge being that modern red and brown algae are differentiated on the basis of colour and cellular structure which are not preserved in the fossil taxa (Hiller and Gess, 1996, Gess and Whitfield). Douglas and Jell (1985) suggested that Buthotrephis trichotoma and B. divaricata [5] should furthermore be transferred from Buthotrephis to Hungerfordia. [6]
A further species, Hungerfordia fionae from the Late Devonian of South Africa is known from the largest sample, analysis of which suggests that variations used to differentiate between H. dichotoma and H. trichotoma may represent growth variations accountable by a single taxon. [3] Hungerfordia fionae fossils are as yet only recorded from the Waterloo Farm lagerstätte in Makhanda, Eastern Cape, South Africa and were first mentioned in the literature in 1991 as ‘terminally-lobed algae’ by Fiona Taylor. [3] With further excavations, in subsequent years, hundreds of specimens of Hungerfordia have been collected, which are housed within the Devonian Ecosystems Laboratory, Albany Museum in Makhanda, Eastern Cape - (with further good examples still being added to the collection during ongoing excavations (2021) by the research team of the Devonian Ecosystems Project). Hungerfordia fionae comprises dichotomous axes and is differentiated from other species by the presence of small bud-like appendages along the margins, which are preserved in a minority of specimens, and may more commonly have been shed in life or during transport. These have been compared to buds produced during the fertile phase of modern Rhodophyte algae. [3] It is believed that H. fionae probably lived in the more marine dominated portion of the Waterloo Farm estuarine system and were drifted further into the estuarine lake system through tidal action. Here they were preserved in large numbers due to anoxic bottom water and still water conditions that allowed for unusual preservation of soft tissues. [4] They are often preserved alongside charophyte algae, representative of fresh to brack conditions, demonstrating the dynamic salinity clines in the estuarine environment, as well as fragments of terrestrial plants and estuarine fauna. [4]
Hungerfordia fionae can be characterised by its thalloid branches with rounded ends that bear bud-like enations (or outgrowths) around the margins. [3] The specimens have an average size of 60 mm long and 60 – 65 mm wide. Despite being incomplete, specimens suggest a four-frond structure emerging from two closely spaced initial bifurcations. [3] The branches are 3–4 mm with bifurcations that occur at irregular intervals and often about 15 mm apart but sometimes at negligible or even greater intervals. [3] The number of bifurcations can be up to seven. [3] One feature that sets Hungerfordia fionae apart from other similar species is the presence of circular bud-like features that are believed to be reproductive structures. [3]
Brown algae, comprising the class Phaeophyceae, are a large group of multicellular algae, including many seaweeds located in colder waters within the Northern Hemisphere. Brown algae are the major seaweeds of the temperate and polar regions. They are dominant on rocky shores throughout cooler areas of the world. Most brown algae live in marine environments, where they play an important role both as food and as a potential habitat. For instance, Macrocystis, a kelp of the order Laminariales, may reach 60 m (200 ft) in length and forms prominent underwater kelp forests. Kelp forests like these contain a high level of biodiversity. Another example is Sargassum, which creates unique floating mats of seaweed in the tropical waters of the Sargasso Sea that serve as the habitats for many species. Many brown algae, such as members of the order Fucales, commonly grow along rocky seashores. Some members of the class, such as kelps, are used by humans as food.
Hyneria is a genus of large prehistoric predatory lobe-finned fish which lived in freshwater during the Devonian period (Famennian).
Bothriolepis was a widespread, abundant and diverse genus of antiarch placoderms that lived during the Middle to Late Devonian period of the Paleozoic Era. Historically, Bothriolepis resided in an array of paleo-environments spread across every paleocontinent, including near shore marine and freshwater settings. Most species of Bothriolepis were characterized as relatively small, benthic, freshwater detritivores, averaging around 30 centimetres (12 in) in length. However, the largest species, B. rex, had an estimated bodylength of 170 centimetres (67 in). Although expansive with over 60 species found worldwide, comparatively Bothriolepis is not unusually more diverse than most modern bottom dwelling species around today.
Groenlandaspis is an extinct genus of arthrodire from the Late Devonian. Fossils of the different species are found in late Devonian strata in all continents except eastern Asia. The generic name commemorates the fact that the first specimens of the type species were found in Greenland.
Pertica is a genus of extinct vascular plants of the Early to Middle Devonian. It has been placed in the "trimerophytes", a strongly paraphyletic group of early members of the lineage leading to modern ferns and seed plants.
Priscomyzon riniensis is an extinct lamprey that lived some 360 million years ago during the Famennian in a marine or estuarine environment in South Africa. This small agnathan is anatomically similar to the Mazon Creek lampreys, but is some 35 million years older. Its key developments included the first known large oral disc, circumoral teeth and a branchial basket.
Serenichthys kowiensis is a fossil species of coelacanth described in 2015 from near Grahamstown in South Africa.
Antarctilamna is an extinct genus of Devonian shark originally exemplified by Antarctilamna prisca from South Eastern Australia and Antarctica. The latest occurring described species is Antarctilamna ultima from the Waterloo Farm lagerstätte in South Africa. Antarctilamna has robust ctenacanthid-like spines which lack a deep insertion area, and are borne in front of the first dorsal fin; in addition to distinctive diplodont teeth with small intermediate cusps. Antarctilamna-like spines, known from the Bunga Beds locality in Australia have been ascribed to A. prisca.
Plesioselachus is an extinct genus of Late Devonian (Famennian) cartilaginous fish with uncertain classification, which contains only one species, P. macracanthus from the Waterloo Farm lagerstätte in South Africa. Known from a single incomplete articulated skeleton and some isolated remains, it is characterized by having a long dorsal spine with length about one third of body length.
The Waterloo Farm lagerstätte is a Famennian lagerstätte in South Africa that constitutes the only known record of a near-polar Devonian coastal ecosystem.
Diplacanthus is an extinct genus of Mid to Late Devonian fish in the class Acanthodii, known as spiny sharks.
Hexachara is a genus of fossil charophyte that is likely to have formed meadows within sheltered oligohaline reaches of lakes.
Naiadites is an extinct genus of thin-shelled non-marine bivalve from the Upper Carboniferous coal-measures of Nova Scotia in Canada.
Octochara is a genus of fossil charophyte from the Famennian. It is one of two genera of charophyte described from the Waterloo Farm lagerstätte in southern Africa. It and Hexachara, from the same locality provide the oldest record of reconstruct able charophytes with in situ oogonia.
Isityumzi mlomomde is fossil lungfish described from fragmentary remains including one complete parasphenoid, tooth plates fragments and scales from the Late Devonian Sarcopterygians. It represents the only record of Late Devonian lungfish remains from western Gondwana.
Yeaia is an extinct genus of brown algae known from the Silurian and Devonian of southern hemisphere locations.
Leptophloeum is an extinct genus of vascular plants in the lycophyte clade. It is widely distributed being, known from the Laurasian and Gondwanan settings between the Devonian and Early Carboniferous periods.
Kowieria is an extinct genus of lycopsid from the Late Devonian from Waterloo Farm, containing the single species Kowieria alveoformis. As of 2021 it is being characterised as incertae sedis. It was first described in 2017 from a black shale layer interbedded with quartzite strata of the Famennian aged Witpoort Formation.
Rinistachya is a genus of Late Devonian sphenopsid, currently containing one species, Rinistachya hilleri. It comprises the only sphenopsid as yet known from the Devonian of Gondwana, and is currently known from only a small number of specimens collected from the main fish layer/lens (MFL) black shale within the Witpoort Formation at Waterloo Farm, Makhanda. It is currently interpreted as a small-sized herbaceous plant. and 'exhibits a novel architecture' that includes apparently plesiomorphic characters, reminiscent of the organisation of the Iridopteridales. Other characters unambiguously nest Rinistachya within the Sphenopsida. This provides strong support for a close relationship between Sphenopsida and Iridopteridales. It is the only known high latitude sphenopsid known from the Devonian, the only other 3 genera, Eviostachya, Hamatophyton and Rotafolia being of palaeotropical provenance.
Beresellaceae is an extinct family of organisms of uncertain affinity, sometimes placed within the Metazoa, but tentatively assigned to the green alga order Dasycladales. Beresellids were cosmopolitan and their fossils are found in strata ranging in age from the late Devonian to the early Permian.
{{cite web}}
: CS1 maint: postscript (link)