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(a1-a6) Paratype OCO-2a-10a, b of †Oreochromimos kabchorensis gen. et sp. nov. (a1, a4) Articulated skeleton of part and counterpart. (a2) Close-up of the neurocranium showing the putative nuchal hump, scales, and the supraorbital sensory canal (all indicated with arrows). (a3) Reconstruction of the caudal skeleton, dotted lines indicate tentative outline due to preservation. (a5) Reconstruction of the posterior lateral line segment (complemented based on holotype). (a6) Flank scales visible between the neural spines beneath the soft rayed part of the dorsal fin. Scale bars: 5 mm (a1-a5), 1 mm (a6). Photos of a1 and a4 by M. Schellenberger at the SNSB -Bavarian State Collection of Palaeontology and Geology (BSPG). Abbreviations: ep, epural; hp, hypurapophysis; hs, haemal spine; hy, hypural plate; ns, neural spine; ph, parhypural; pu, preural vertebra; un, uroneural; us, urostyle.
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A new genus and species of fossil cichlid fishes of middle Miocene age (12.5 Ma) is described from the Ngorora fish Lagerstätte (Tugen Hills, Kenya) in the East African Rift Valley. Parsimony analysis of morphological characters using published phylogenetic frameworks for extant cichlids combined with the application of a comprehensive best-fit app...
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Context 1
... OCO-2c-4a shows that longest ray extends to penultimate vertebra (Fig. 5a1); in all other specimens rays visible only up to middle of caudal peduncle. As usual in cichlid fishes, the first two anal fin spines are supported by a robust, relatively long pterygiophore composed of two fused elements; it inserts before the first caudal vertebra (Fig. 4a5). Last spine and rays (except last two rays) each supported by pterygiophores, decreasing in size backwards; last pterygiophore supports two ...
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... 1 and the urostyle, but is not connected to the latter. It bears a posteriorly directed hypurapophysis (Figs 4a3 and 5a4). The urostyle forms the complement for the uroneural bone, which is positioned between hypural plate 5 and epural 2. The preural centrum 2 either has a neural arch without a neural spine (Fig. 4a3) or a reduced neural spine ( Fig. 5a4), and an autogenous haemal arch with a well-developed spine that broadens distally. The preural centrum 3 has fully developed neural and haemal arches with complete spines that extend to the procurrent rays (Figs 4a3 and ...
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... Scales cycloid and variable in sizes and shapes. Large scales with 8-12 radii and mostly continuous circuli occur on the flank, caudal peduncle, and caudal fin base; a few have disintegrated circuli in the caudal field (Fig. 4a6). Further large scales (albeit slightly smaller than those just mentioned) cover cheek (which is fully scaled), opercle, subopercle, and interopercle; opercle with two vertical rows of scales running along the anterior margin and one horizontal row along the dorsal margin. Lacrimal bone, together with dorsal, anal, and pelvic fins ...
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... tips of the neural spines and extend to the fifth caudal vertebra. Posterior segment always incompletely preserved, but the holotype and paratype OCO-2a-10a, b reveal different parts of it. It starts at the level of the first caudal vertebra, overlaps the proximal to middle parts of the haemal spines, and is covered by at least 10 tubular scales (Fig. 4a5) Table S18 for characters and states). Additional details are provided in the Methods ...
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... ratios and relative scale sizes (in % of SL and BL) based on 12 ethanol-preserved specimens of Pseudocrenilabrus. The results indicate that flank scales are generally ovate in Pseudocrenilabrus (Fig. 10e,f), with a width/length ratio mostly between 1.2-1.3 (Suppl. Data 3, Table S10). In contrast, the fossil taxon has round flank scales (Fig. 4a6), and their width/length ratio is 1.0 (Suppl. Data 3, Table S10). In addition, in all investigated species of Pseudocrenilabrus flank scales are larger than in the fossil, with lengths differing by a factor of 1.6-2.0 and 1.4-1.8 (in % of SL and BL, respectively), and widths by a factor of 1.7-2.6 and 1.5-2.4 (in % of SL and BL, ...
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... lateral-line segment (vs. >10 in †Om. kabchorensis), which is running immediately adjacent to the vertebral column (vs. slightly below the vertebral column in †Om. kabchorensis), and the posterior trunk segment is simply an extension of the anterior segment, without any overlap (vs. overlap by several scale rows in †Om. kabchorensis; see Fig. ...
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Miocene invertebrates hosted at MSN in Florence
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... However, little is known about the morphological synapomorphies that define each of these lineages and, as mentioned in Reichenbacher and Bannikov (2022), a phylogenetic matrix based on morphology that includes members of all 14 lineages is not available. Hence, the 'best-fit' approach sensu Penk et al. (2019) is used in the following to analyse whether †Moldavigobius gen. nov. ...
The middle Miocene (upper Serravallian, lower Volhynian) deposits at Karpov Yar near Naslavcea, northern Moldova, are among the few settings in which fossil fish are preserved with otoliths in situ. Here, we describe the new gobiid † Moldavigobius helenae gen. et sp. nov. from this locality. The taxon is characterized by small size (up to 34.2 mm SL), a compact body (body depth 17–21% SL), a fan-shaped caudal fin, large ctenoid scales (< 30 scales in the longitudinal row) and nearly square otoliths (sagittae) with a slender, shoe sole-shaped sulcus. It has 27 vertebrae, six spines in the first dorsal fin, one spine and 11 soft rays in both the second dorsal and the anal fin, 15–17 pectoral-fin rays, and 17 (9/8) segmented caudal-fin rays. The meristic characters of † Moldavigobius gen. nov., together with its sagitta shape, suggest a relationship with Lesueurigobius Whitley, 1950, but its fan-shaped caudal fin and the unique sulcus contour of the otoliths preclude its attribution to that genus. In addition, we re-assign an otolith-based species previously described as Knipowitschia suavis Schwarzhans, 2014 as a second member of † Moldavigobius gen. nov. Accordingly, † Moldavigobius gen. nov. was represented by at least two species in the Serravallian of the Eastern Paratethys († M. helenae gen. et sp. nov., † M. suavis nov. comb.). Moreover, † M. suavis is also known from the Serravallian ichthyofauna of the SE Mediterranean. † Moldavigobius gen. nov. thus demonstrates the key role of fossil skeletal material with otoliths in elucidating the ancient diversity of the Gobioidei.
... Fossil cichlids can be difficult to assign to extant lineages because the extant forms are distinguished predominantly based on softtissue characters that do not preserve well (or at all) in the fossil record. A new method of assigning fossil cichlids to extant lineages, termed 'the best fit approach' was proposed by Penk et al. (2019) and has since been used by others (e.g., Přikryl et al., 2022) with some success. Here, a new species of cichlid is described from Oligocene deposits of the Daban Group of northern Somalia. ...
... This new species joins the Eocene Mahengechromis spp., and Oligocene Libyachromis fugacior and Macfadyena dabanensis as the only named Palaeogene African cichlids (Van Couvering, 1982;Murray, 2000;Přikryl et al., 2022). The new species is assessed using the methods of Penk et al. (2019) to determine the likely relationships. ...
... Photographs of the holotype material of Macfadyena dabanensis from presumed Oligocene deposits of Somalia were kindly provided by Matt Riley, Sedgwick Museum of Earth Sciences, University of Cambridge. very poorly resolved tree, the Somali cichlids were analysed using the "best-fit approach" of Penk et al. (2019) to determine the most-probable relationships of the Libyan fossil material. This method was devised specifically for fossil cichlids, to overcome issues that are associated with lack of soft-tissue preservation and consequent lack of data to include fossils in phylogenetic data sets of extant cichlids. ...
Cichlid fishes are an important component of the African freshwater ecosystem and the evolution of this group has captured the interest of ichthyologists for many decades. The distribution of cichlid fishes in both Africa and South America, and the apparent reciprocal monophyly of the cichlids in the two areas, has led to differences in opinion as to whether their modern distribution reflects a dispersal event from Africa to South America or was the result of a vicariant event–the break-up of the two continental masses in the mid-Cretaceous. If the vicariant event were the cause of the modern distribution, this would indicate an age for the family of at least 120 million years; however, the fossil record indicates a younger, Cenozoic, age for the family. The known fossil taxa in Africa often are difficult to assign to extant tribes which creates inaccuracies when they are used to date lineages within Cichlidae. The difficulty of assigning fossil cichlids to modern lineages is caused by most of these lineages being recognized based on DNA or soft-tissue characters, which are generally not preserved in fossils. This hampers our understanding of the early history of the family. Despite this, new African cichlid fossils that have been described in the past two decades and a new technique to determine relationships of these fossils are beginning to elucidate the early history of the family in Africa. Here the Palaeogene (Eocene and Oligocene) cichlids of Africa are reviewed and a new taxon from the Oligocene of Somalia, Somalichromis hadrocephalus gen. et sp. nov. is described.
... AMM). A number of Miocene taxa have also been associated with the "haplotilapiines" or with more specific lineages (Kevrekidis et al. 2019(Kevrekidis et al. , 2020Penk et al. 2019) including the EAR (Altner et al. , 2020Altner & Reichenbacher 2021). Less is known about the fossil history of the non-"haplotilapiines", with only Tylochromini so far documented (in the form of a lower pharyngeal jaw from the early Oligocene of Egypt [Murray 2002] and remains from the middle Eocene of Libya [Otero et al. 2015]). ...
... Given the expected lack of resolution of this first phylogenetic analysis, we then used the "best-fit approach" of Penk et al. (2019) to determine the most-probable relationships of the Libyan fossil material. Penk et al. (2019) devised this method specifically for fossil cichlids, to overcome the issues noted above that are associated with phylogenetic analysis of this group. ...
... Given the expected lack of resolution of this first phylogenetic analysis, we then used the "best-fit approach" of Penk et al. (2019) to determine the most-probable relationships of the Libyan fossil material. Penk et al. (2019) devised this method specifically for fossil cichlids, to overcome the issues noted above that are associated with phylogenetic analysis of this group. Penk et al. (2019) examined the large assemblage of African cichlids referred to as "haplotilapiines" (e.g. ...
Two species of fossil cichlid are described from Oligocene deposits of Libya. One is formally described as Libyachromis fugacior gen. et sp. nov. This species is considered to be the sister group to most of the remaining members of the African subfamily Pseudocrenilabrinae, perhaps close to Heterochromis, and is characterized by two predorsal bones, dorsal fin with 12–14 spines and 9–12 rays, 24–28 vertebrae, cycloid scales present on body and head including cheek, and only unicuspid teeth present on the oral and pharyngeal jaws. The second fossil form is less complete, and so we do not formally name it, but it appears to be most closely related to Tylochromis, and thus we place it in the Tylochromini. These new fossils increase our understanding of the diversity of cichlid lineages in the Palaeogene. The unnamed fossil supports the presence of Tylochromini in the Eocene and Oligocene of North Africa, as was previously suggested by the remains of partial lower pharyngeal jaws from Egypt and Libya. The named fossil adds to the known diversity of early Cenozoic cichlids that document the presence of probably Heterochromini along with Tylochromini in North Africa.
... The assignment of the new fossil species to one of these gobiid lineages would require a phylogenetic matrix based on morphology comprising members of all lineages, which is currently not available. Hence, the following considerations are based on literature data (see Table 2), the comparative material (Appendix Table, Supplementary Data 2), and the best-fit approach sensu Penk et al. (2019). The aim is to determine to which of the extant gobiid lineages the new fossil genera are most likely to be related based on the numbers of shared characters. ...
... The discovery of four new gobiid genera that most likely formed a monophyletic group in the lower Volhynian of northern Moldova indicates that the overall character of European gobiid diversity about 12 Ma was clearly different from that seen today. On the basis of the best-fit approach sensu Penk et al. (2019), the new fossils were classified as a possible stem lineage of the European Aphia lineage, which is represented today by A. minuta and five species of Lesueurigobius. Given the long stratigraphic range of Lesueurigobius, for which otoliths are known from as far back as the late Oligocene, the presence of a stem lineage of its clade (the Aphia lineage) is not unexpected. ...
This article is part I of our study on a highly diverse assemblage of goby species from the lower Volhynian (lower Sarmatian sensu lato) deposits of northern Moldova (Karpov Yar, Naslavcea, western sector of the Eastern Paratethys). Six species, including five new ones, representing four new genera are described. All share the following unique features: large numbers of rays in the second dorsal fin (14–16) and anal fin (13–15) and, where preserved, a caudal fin of longish to lanceolate shape. They resemble the present-day European genus Lesueurigobius Whitley, 1950, but, based on their otoliths preserved in situ, they cannot belong to this genus. The new fossils most likely represent a stem lineage of the European Aphia lineage, and indicate that the diversity of gobiid lineages 12 million years ago differed clearly from that observed today.
... Morphological similarity among elements of many cichlid genera means that individual diagnostic elements are lacking. Although the 'best-fit' approach developed and used by Penk et al. (2019) and Altner et al. (2020) has provided good results for assigning articulated fossil cichlid material to tribe using a large number of comparative species, we are not yet able to assign isolated cichlid elements to lower taxonomic levels. Rare extant cichlid genera can achieve close to one meter in total length (e.g., Matthes, 1961), but total lengths of Oreochromis, present today in the Awash River (see below), range from ca. 9-61 cm (Froese and Pauly, 2019). ...
Fossil fish remains from Gona, Ethiopia, were recovered along with those of other vertebrates by the Gona Paleoanthropological Research Project team (GPRP) in the late 1990s and early 2000s from Pliocene and Pleistocene deposits. The early Pliocene fish were recovered from natural depositional contexts, whereas the early Pleistocene fish were associated almost completely with archeological contexts. Analysis of the fossils provides new information on the Pliocene and Pleistocene fish taxa from deposits associated with the Awash River system in the Afar Depression, Ethiopia. Six families are represented in the fossil assemblages, including one not previously reported from the Pliocene Awash River system. Based on the methodology of a previous study, we test the accuracy of using habitat preferences of modern fish taxa to infer the preferences of the same fossil taxon. Our findings contribute to the reconstruction of the paleoecology of the Pliocene Awash river and lakes. The presence of several hyperostotic cichlid bones in both the Gona and Middle Awash project areas indicates that periods of stability in the lakes and rivers of the Awash River system were punctuated by occasional periods of extreme changes in water levels and water chemistry, resulting in intense soda conditions, which would eradicate most fish taxa. Fish bones recovered from the localities with archeological contexts differed in taxonomic composition and diversity from the naturally deposited assemblages, suggesting the possibility that these remains were selected and accumulated by humans.
... Furthermore, Van Couvering (1982) implied that †"S." martyni lived under alkaline conditions (pH about 9-10), as the mineral analcime, which is indicative for high alkalinity (Hay, 1966(Hay, , 1970, was abundant in the Miocene sediments that yielded this fossil species. More recently, another fossil species, †Oreochromimos kabchorensis Penk, Altner, Cerwenka, Schliewen, and Reichenbacher, 2019, characterized by a morphology intermediate between that of Oreochromis (Alcolapia) and all other Oreochromis, was described from the Ngorora Formation of the Tugen Hills . However, Penk et al. (2019) were cautious not to directly suggest a relationship with Oreochromis (Alcolapia) pending further information. ...
... More recently, another fossil species, †Oreochromimos kabchorensis Penk, Altner, Cerwenka, Schliewen, and Reichenbacher, 2019, characterized by a morphology intermediate between that of Oreochromis (Alcolapia) and all other Oreochromis, was described from the Ngorora Formation of the Tugen Hills . However, Penk et al. (2019) were cautious not to directly suggest a relationship with Oreochromis (Alcolapia) pending further information. ...
... 2). Apart from abundant finds of fossil mammals, turtles, crocodiles and plants, the Ngorora Formation hosts a fossil-fish Lagerstätte, characterized by numerous assemblages of cichlid fish fossils, especially in the sediments comprising the Members C to E of the Kapkiamu sub-basin (Bishop and Pickford, 1975;van Couvering, 1982;Rasmussen et al., 2017;Altner et al., 2017;Kevrekidis et al., 2019;Penk et al., 2019). ...
The African Cichlidae Oreochromis (Alcolapia) and Oreochromis amphimelas can survive in extremely alkaline environments and represent the only known modern alkaliphilic cichlid fish found in Africa. The presence of fossil cichlids from the Miocene of central Kenya (Tugen Hills) that are morphologically similar to Oreochromis (Alcolapia) has been noted in previous works, but the conclusions remained tentative. The purpose of this study is to examine newly discovered fossil cichlids from the Tugen Hills and to compare their osteology with that of extant Oreochromis (Alcolapia). This is performed based on a comprehensive collection of comparative material, using microscopy and computed microtomography (μCT). We provide a revised diagnosis for the genus †Rebekkachromis, and revise its systematic relationships by assigning it to the Oreochromini (rather than to the Etiini). Two new species of †Rebekkachromis are described, i.e., †R. valyricus, sp. nov., and †R. vancouveringae, sp. nov., and a morphologically diverse assemblage of co-occurring †Rebekkachromis specimens is documented. Moreover, we found that †Rebekkachromis had three sensory canal pores (instead of four) on the lower arm of the preopercle, a feature that distinguishes both the modern Oreochromis (Alcolapia) and our fossil specimens from almost all other modern African cichlid fish. Our new data indicate that alkaliphile cichlids similar to Oreochromis (Alcolapia) were present in Central Kenya about 10-13 Ma ago and that the ability of African cichlid fishes to thrive in highly alkaline waters had already developed by that time. http://zoobank.org/urn:lsid:zoobank.
... Neither study, however, provided morphological characters to define this clade, which is well supported by mitochondrial DNA analyses, but nevertheless the term has become increasingly accepted in the literature (e.g. Altner et al. 2017, Penk et al. 2019. Table 1 provides a cursory overview of previous studies using the term and of the assignment of taxa placed within the Pseudocrenilabrus group. ...
Two monotypic haplochromine cichlid genera (Teleostei: Cichlidae) of the Pseudocrenilabrus group are described from northern Zambia. One new genus is Palaeoplex gen. nov., with Pa. palimpsest sp. nov. as the type species, from the Luongo and Kalungwishi Rivers (Upper Congo drainage, Luapula subdrainage). It is diagnosed by a unique combination of morphological characters: (1) a fully developed infraorbital series without a distinct gap between the lachrymal and second infraorbital bone, (2) fused hypuralia 1+2 and hypuralia 3+4, (3) molariform teeth on the sagittal series of the lower pharyngeal jaw, and (4) a large maximum size. The second new genus, Lufubuchromis gen. nov., with L. relictus sp. nov. as the type species, is restricted to the upper Lufubu River catchment (Upper Congo drainage, Lake Tanganyika subdrainage). It is diagnosed by a unique combination of morphological characters: (1) a fully developed infraorbital series without a distinct gap between the lachrymal and second infraorbital bone, (2) fused hypuralia 1+2 (rarely with a visible suture) and fused hypuralia 3+4, (3) a unique male coloration pattern, i.e. deep crimson red colored areas on the anterior ventral flank parts, chest and belly and on the lower head; remaining parts of flanks and caudal peduncle bluish), and (4) a Pseudocrenilabrus blotch present in both sexes. Both new genera are compared with all remaining taxa of the Pseudocrenilabrus group and with all representatives of all other major haplotilapiine lineages.
... According to Cabej (2019), up to 3000 fish species ore more have been described worldwide from the family Cichlidae making them the largest group among the vertebrates. Of these, at least 1100 cichlid species have been reported in Africa (Stefanie et al., 2019) with only 12 species in Nigeria (Olopade and Dienye, 2018). Although most species especially ornamental cichlids are found in East Africa notably Lake Malawi, Lake Victoria and Lake Tanganyika, West Africa is competitively a repository of cichlid species (Kinyage and Lamtane, 2018). ...
Cichlids are well distributed within the Neo-tropical and Afro-tropical bio-geographic zones. In Afro-tropics, they are found to be widespread in freshwaters including rivers, streams, lakes and dams. In this study, the general objective was to examine their relative abundance and distribution in the Great Kwa River, Nigeria. A one-year monthly sampling for cichlids was undertaken from November 2017 to October 2018 with local traps, hook and line as well as multi-mesh gillnets that ranged between 30 mm to 80 mm. Relative abundance and t-distribution test were used respectively to examine the abundance and distribution of cichlid species in the two sites of the river. Results showed that a total of 587 individual cichlids were caught from Esuk Anantigha (60.99%) and Esuk Atu (39.01%). Species collected include Oreochromis niloticus (45.14%), Tilapia zillii (36.46%) and Chromidotilapia guntheri (18.40%) in order of abundance. Independent t-test revealed significant seasonal and spatial disparities in relative abundance and distribution at P<0.01. Higher cichlid abundance was observed during dry season with distribution skewed towards Anantigha station. Thus, there is need to control anthropogenic activities in the area to ensure sustainable biodiversity and conservation of aquatic resources.
Fossil cichlids from East Africa offer unique insights into the evolutionary history and ancient diversity of the family on the African continent. Here we present three fossil species of the extinct haplotilapiine cichlid †Baringochromis gen. nov. from the upper Miocene of the palaeolake Waril in Central Kenya, based on the analysis of a total of 78 articulated skeletons. †Baringochromis senutae sp. nov., †B. sonyii sp. nov. and †B. tallamae sp. nov. are superficially similar, but differ from each other in oral-tooth dentition and morphometric characters related to the head, dorsal fin base and body depth. These findings indicate that they represent an ancient small species flock. Possible modern analogues of palaeolake Waril and its species flock are discussed. The three species of †Baringochromis may have begun to subdivide their initial habitat by trophic differentiation. Possible sources of food could have been plant remains and insects, as their fossilized remains are known from the same place where †Baringochromis was found.
Background:
The diversification process known as the Lake Tanganyika Radiation has given rise to the most speciose clade of African cichlids. Almost all cichlid species found in the lakes Tanganyika, Malawi and Victoria, comprising a total of 12-16 tribes, belong to this clade. Strikingly, all the species in the latter two lakes are members of the tribe Haplochromini, whose origin remains unclear. The 'out of Tanganyika' hypothesis argues that the Haplochromini emerged simultaneously with other cichlid tribes and lineages in Lake Tanganyika, presumably about 5-6 million years ago (MYA), and that their presence in the lakes Malawi and Victoria and elsewhere in Africa today is due to later migrations. In contrast, the 'melting pot Tanganyika hypothesis' postulates that Haplochromini emerged in Africa prior to the formation of Lake Tanganyika, and that their divergence could have begun about 17 MYA. Haplochromine fossils could potentially resolve this debate, but such fossils are extremely rare.
Results:
Here we present a new fossil haplochromine from the upper Miocene site Waril (9-10 million years) in Central Kenya. Comparative morphology, supported by Micro-CT imaging, reveals that it bears a unique combination of characters relating to dentition, cranial bones, caudal skeleton and meristic traits. Its most prominent feature is the presence of exclusively unicuspid teeth, with canines in the outer tooth row. †Warilochromis unicuspidatus gen. et sp. nov. shares this combination of characters solely with members of the Haplochromini and its lacrimal morphology indicates a possible relation to the riverine genus Pseudocrenilabrus. Due to its fang-like dentition and non-fusiform body, †W. unicuspidatus gen. et sp. nov. might have employed either a sit-and-pursue or sit-and-wait hunting strategy, which has not been reported for any other fossil haplochromine cichlid.
Conclusions:
The age of the fossil (9-10 MYA) is incompatible with the 'out of Tanganyika' hypothesis, which postulates that the divergence of the Haplochromini began only 5-6 MYA. The presence of this fossil in an upper Miocene palaeolake in the Central Kenya Rift, as well as its predatory lifestyle, indicate that Haplochromini were already an important component of freshwater drainages in East Africa at that time.
