Biodiversity of Cypriniform Fossils
Fossil Cypriniform Fish ToL Portal:
Goals for the Paleontological Aspects of The Cypriniformes Tree of Life Project:
The primary goal of examining the rich history of cypriniform fossil diversity in this Tree of Life initiative is to bring together the diversity of morphological characters of selected, well-preserved and prepared fossil cypriniform species from different continents and geological time periods and develop a phylogeny of the Cypriniformes, both Extinct and Extant. This phylogeny will form the basis to examine many important questions in comparative biology and science in general but with the fossil taxa it will for the basis for the biogeographic interpretations of past and present distribution of cypriniforms.
Fossil cypriniforms are known from the first half of the 19 century. The first description of a fossil assigned to Cyprinus was by Bronn (1830), an assignment based on overall similaries (e.g., scales and size of the mouth) with the extant Cyprinus carpio. Cyprinus coryphaenoides Bronn was promptly reassigned to the extinct genus Leptolepis by Agassiz (1832).
The first descriptions of fossil cypriniforms are those by Agassiz (1833-1844) and included several genera in his Cyprinoides. Agassiz’s classification (see Fig. 1) was largely based on the structure of scales. He classified the fishes into four orders: Cycloïdes, Ctenoïdes, Ganoïdes and Placoïdes. His Cyprinoides were included in the Cycloïdes together with some other teleosts. Although at the same time, Müller (1844) created the subclass Teleostei, this did not have much influence on Agassiz’s interpretations of the fossil record, due to the fact that Müller’s subclasses were founded on soft anatomical features only (see Arratia 2001). Agassiz’s classification was replaced because it did not contain generalizations of fundamental value. Nevertheless, concerning fossil cypriniforms, his work cannot be ignored because he provided the first descriptions of extinct representatives for some genera on material deposited in the Muséum national d’ Histoire naturelle in Paris. His descriptions include three species of Cobitis (from Öhningen and Monbach), one of Acanthopsis (= Acantopsis; Öhningen), three species of Tinca (Öhningen and Steinheim), ten of Leuciscus (from different German localities; most of them now included in Palaeoleuciscus; Fig. 2), two of Aspius (Öhningen and Ménat), two of Rhodeus (Öhningen), two of Cyclurus (= amiiform; Gaudant 1987; Öhningen and Ménat), and one species of Gobius (Öhningen). Agassiz’s work was followed by other classical descriptions like those of Cope on the Eocene-Oligocene Amyzon (1872) and Amyzon brevipinne Cope, 1893 from the USA.
In general, the available information on fossil cypriniforms is quite diverse and based on material recovered in Europe, Asia, Africa, and South America (see Table 1 (.pdf file)). Many of these records are doubtful, because the quality of the material or the age of the deposits are unprecise, and additionally, a significant part of the material is fragmentary or represented by pharyngeal teeth only. For instance, Molinichthys inopinatus Gayet, 1982 from the Upper Cretaceous of Bolivia, is based on a fragment of a supposed pharyngeal bone. If it can be shown in the future that this specimen belongs to a cypriniform, then it would be the oldest known record of the group. Additionally, part of the ambiguity lies in the fact that cypriniforms are not found in South America today. However, it is important to keep this finding in mind because other fishes, e.g., lepisosteids, that are not present in South America today, are presently known by at least four complete specimens of Early Cretaceous age, recovered recently in Brazil (see Wenz and Brito 1996). Disregarding Molinichthys, the oldest known record of cypriniforms would be a catostomid (Amyzon) from the lower Paleocene (?Danian), Paskapoo Formation, Alberta, Canada (Wilson 1980).
Among cyprinids, the oldest record is Parabarbus sp. from the lower Eocene of Kazakhstan (Sytchevskaya, 1986). In general, the age of the earliest cyprinids is difficult to document precisely, because of their occurrence in freshwater environment. The precise age of many Asian records (e.g., Chang and Chow 1986, Sytchevskaya 1986, Zhou 1990) is not known precisely (Patterson 1993: 628).
Fossil cobitids are not abundant. The oldest known cobitid is Cobitis centrochir Agassiz, 1835 (Fig. 3) from the middle Miocene of Öhningen, Bavaria, Germany, a famous locality bearing different cypriniforms.
An overview of the literature tells us that main efforts during the twenty century have centered in (1) describing new species (e.g., Amyzon aggregatus Wilson, 1977, A. gosiutensis Grande et al., 1982, A. zaissanicus Sytchevskaya, 1983, Eocyprinus liui Chang et al. 1996, Miheichthys shandoensis Zhou, 1990, Plesioleuciscus nitidus Zhou, 1990, Xenocypris yushensis Liu and Su, 1962), (2) describing new subspecies (e.g., Böhme 1996), (3) synonymizing taxa, a particularly notorius situation in Europe (see for instance Gaudant 1993, 1996; Böhme 1996), (4) postulating probable geographic relations between taxa and between basins to explain the history of some European basins and Asian regions and of some regional ichthyofaunas (e.g., numerous others papers by J. Gaudant, Chang et al., 1996, Chang et al., 2001, Popov et al , 2001, 2002), (5) postulating probable biogeographic relationships based on the presence of certain fossils, e.g., North America China Kazakhstan (e.g., Sytchevskaya 1986; Chang and Chow 1986; Smith, 1992;Chang et al, 2001), or certain periods in Europe and Asia (for a revision see Popov et al. 2001a, b), (6) postulating paleoecological conditions, based on the ichthyofauna, in different European geological ages (e.g., Gaudant 1978, 1985, 1993, Popov et al., 2001, 2002). The analysis of the literature reveals that comprehensive morphological studies of fossil cypriniforms are rare (e.g., Obrhelová, 1971; Grande et al., 1982) and in most of the cases comparison with extant species are lacking. Many of the new taxa are based on isolated pharyngeal teeth, as is the case of most African records of Barbus and Alestes (e.g., Greenwood. 1972, 1974, see Stewart, 2001 for a list of localities). Morphological descriptions, in most cases, are very incomplete and do not reflect the quality of preservation of the fossil specimens. Additionally, a careful exmination of the literature on fossil cypriniformes reveals that a worldwide comparison of the cypriniform fossil record has never been done.
Since most of the studies have been centered in basic taxonomy, the revision of the literature reveals that systematics studies including fossil fishes are rare and centered in specific groups). For instance: The only available contribution with a phylogenetic analysis (but not using phylogenetic programs) including fossils is that by Böhme (1996) on the European species and subspecies of the genus Palaeoleuciscus. Smith (1992) is exceptional by including two North American species of Amyzon and one extinct species of Moxostoma in his phylogenetic and biographical analyses of the Catostomidae.
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