Hermann Karsten (1817–1908): a German naturalist in the Neotropics and the significance of his paleovertebrate collection

: Abstract. During the mid-19th century, the German naturalist Hermann Karsten conducted a 12-year exploration (1844–1856) in the territories of Ecuador, New Granada (now Colombia) and Venezuela, allowing him to produce important botanic, geographic and geologic descriptions with valuable information that permits us to refer to him as a pioneer in many of these topics.With his return to Europe, abundant geological, paleontological and living plant specimens were brought and housed in European museums and botanical gardens. The Karsten collection included an important invertebrate collection from the Cretaceous of the Andes of Colombia and Venezuela, which was studied and published by himself and the renowned German paleontologist Leopold von Buch, filling a large void in the knowledge about ancients faunas. H. Karsten’s vertebrate collection was never illustrated or subjected to a detailed taxonomic study, being mentioned in scientific publications in a repetitive manner and with incorrect taxonomic and provenance information. More than 160 years after they were collected, we carried out a taxonomic revision of all H. Karsten’s vertebrate specimens from Colombia and Venezuela, which are housed in the Museum of Natural History in Berlin. These specimens are represented by cranial and postcranial elements of megafauna, which include Megatheriidae, Mylodontidae and Glyptodontidae (Xe-narthra), Toxodontidae (Notoungulata), Gomphotheriidae (Proboscidea), and many other indeterminate mammal remains. This revision is intended to clarify the taxonomy and provenance of the specimens, emphasizing the historical importance of this fossil collection and its significance for the paleontology of the region. Abstract. During the mid-19th century, the German naturalist Hermann Karsten conducted a 12-year exploration (1844–1856) in the territories of Ecuador, New Granada (now Colombia) and Venezuela, allowing him to produce important botanic, geographic and geologic descriptions with valuable information that permits us to refer to him as a pioneer in many of these topics. With his return to Europe, abundant geological, paleontological and living plant specimens were brought and housed in European museums and botanical gardens. The Karsten collection included an important invertebrate collection from the Cretaceous of the Andes of Colombia and Venezuela, which was studied and published by himself and the renowned German paleontologist Leopold von Buch, ﬁlling a large void in the knowledge about ancients


Introduction
Dr. Karl Hermann Gustav Wilhelm Karsten (1817Karsten ( -1908 (Fig. 1) was a Prussian naturalist from Stralsund (northern Germany), who, using his own economic resources, conducted a 12-year long exploration in the Neotropical territories of Venezuela (1844-1847 and 1848-1852) and the Republic of New Granada (now Colombia) and Ecuador (1852)(1853)(1854)(1855)(1856) (Röhl, 1944;Alert, 1999). Alexander von Humboldt provided H. Karsten with a letter of introduction to the Venezuelan president, requesting collaboration for the trips and intellectual aim of the young scientist (Röhl, 1944). The previous training of H. Karsten as an apprentice in pharmacy and natural sciences was useful during his explorations in South America, which resulted in detailed descriptions of botany, entomology, geography and geology (Karsten, 1886;Röhl, 1944;Hedberg, 1974;Alert, 1999;Aalto, 2015). During his travels through Venezuela, New Granada and Ecuador, H. Karsten met well-known figures of the political, medical and the natural sciences, including Agustín Codazzi, Alexander Benitz, Karl Moritz, August Gottfried Knoche and Francisco José de Caldas; some of them shared long days of exploration and collection of specimens (Röhl, 1944;Tryon, 1963;Alert, 1999).
Hermann Karsten was engaged mainly in the study of tropical plants, which resulted in many publications, his best known work being Florae Columbiae Terrarumque Adiacentium Specimina Selecta in Peregrinatione Duodecim Annorum Observata Delineavit et Descripsit, published in two volumes from 1858 to 1869 (Tryon, 1963). Additionally, H. Karsten was acquiring much geological information during his travels, especially about Cretaceous and Cenozoic rocks, observations and descriptions that are all the more remarkable because it is considered that he was primarily a botanist (Hedberg, 1974). His geological contributions (Venezuela, New Granada and Ecuador) included about 21 publications (summarized in Hedberg, 1974, 36-43), with valuable contributions on geomorphology, geological cartography, mineralogy, orogeny, paleontology, petrography and volcanology, among others subjects, Karsten being a regional pioneer in many of these topics. He published comments about the geology of the Island of Curaçao (Karsten, 1853), which he visited in the middle of his journey from Venezuela to New Granada in 1852. Thirty years after his return from South America, H. Karsten (1886) published his best-known geological contribution Géologie de l'ancienne Colombie bolivarienne: Vénézuela, Nouvelle-Grenade et Ecuador, a comprehensive summary of his geological results of 12 years of exploration. In this contribution, written in a diary style, H. Karsten reviewed previous geological, climatic, topographic/vegetation and soil observations, including many references to fossil finds (Karsten, 1886). In these and other publications (e.g., Karsten, 1849Karsten, , 1858Karsten, , 1886, Karsten also included many references to botanical and animal fossils. These fossils, especially invertebrates such as Cretaceous bivalves, echinoids and ammonites, were brought to and deposited in European museums, where some of them were studied by himself and by the renowned paleontologists Leopold von Buch and Charles Louis Perceval de Loriol (von Buch, 1850;Karsten, 1858Karsten, , 1886De Loriol, 1876). Using H. Karsten's specimens from the Andes of Lara, von Buch described for the first time a fossil species from Venezuela: Ammonites ( = Anapuzosia) tucuyensis (von Buch, 1850). Karsten (1851, pp. 445, 465) also mentioned the finding of amber in Venezuela, specifically from the states of Falcón and Lara; in the latter, he found abundant well-preserved fragments with embedded wasps and bees.

Hermann Karsten's fossil mammals
The taxonomic composition of H. Karsten's fossil specimens includes 60 cranial and postcranial remains attributed to "ground sloths", large glyptodonts (close relatives of armadillos), "South American native ungulates", proboscideans and other indeterminate mammalian remains.

Glyptodonts (Xenarthra: Cingulata Illiger 1811)
The specimens are represented by a few cranial and postcranial elements ( Fig. 6l-z), all found in the San Juan de Los Morros locality (Tables 1-2). Cranial elements are represented by an anterior fragment of a right hemimandible (MB.Ma. 33532) preserving the molariforms 1-3 ( Fig. 6l-n), and two upper isolated molariforms (MB.Ma. 33532) corresponding to the two first (Mfs 1 and 2) ( Fig. 6o-r). A comparison with complete material (e.g., MCNC s/n; see Carlini et al., 2008;Oliveira et al., 2010) shows that these remains from San Juan de Los Morros belong to Glyptotherium cf. G. cylindricum Brown, 1912. The mandible of G. cf. cylindricum is slender and morphologically similar to that of Glyptotherium texanum Osborn, 1903. It differs clearly from that of Glyptodon Owen, 1839, which has a greater robustness in this taxon. In turn, the preserved upper and lower molariforms are trilobate (Fig. 6o-r), as observed in the genus Glyptodon, and morphologically similar to that of Glyptotherium cylindricum. As in Glyptodon the molariforms show an asymmetric development of the three lobes, being more developed labially than lingually. With regard to the isolated postcranial elements, the osteoderm (MB.Ma. 3353-1) could correspond to an accessory osteoderm of the caudal border of the dorsal carapace or, alternatively, to the caudal rings of the caudal armor ( Fig. 6st). Specimens MB.Ma. 3353-2-6 ( Fig. 6u-z) correspond to carpal-metacarpal elements. However, the absence of diag- nostic characters in these elements precludes a more specific identification than Glyptodontidae indet.

"South American native ungulates" (Notoungulata: Toxodontidae Gervais 1847)
One possible tooth fragment referred in the MB.Ma. catalog as "Toxodonta" (MB.Ma. 33517) from San Juan de Los Morros (the specimen could not be located in the collection) and a postcranial element assigned to a pisiform (MB.Ma. 33542) of indeterminate laterality (Fig. 7a-d) from the Paraguaná Peninsula (Tables 1-2) are the only specimens assigned to this group in the H. Karsten collection. The articular surfaces of the pisiform (81.6 mm long) are slightly eroded. A comparison with some pisiforms of Toxodon Owen, 1837, from Argentina (MLP and PIMUZ) shows that the specimen from Venezuela is apparently much larger and robust. Mixotoxodon larensis Van Frank, 1957, is the only species known from the Pleistocene of Venezuela (Rincón, 2011;Carrillo-Briceño, 2015), and its paleogeographic distribution possibly ranges from the United States to the north of Argentina (Carrillo-Briceño, 2015). Although dental characters have been used to distinguish Toxodon from Mixotoxodon (e.g., Van Frank, 1957;Rincón, 2011), little is known about their postcranial differences, especially for the few remains that have been assigned to Mixotoxodon. The absence of a stratigraphic context and of diagnostic characters in the specimen from Paraguaná Peninsula precludes a more specific identification than Toxodontidae indet.

Proboscideans (Proboscidea: Gomphotheriidae Hay, 1922)
The fossil specimens are represented only by four postcranial elements ( Fig. 7e-o, Table 1); all of them were found in the "Barbacoas-Candelillas" locality, Colombia (Table 2). MB.Ma. 17152 corresponds to a thoracic vertebra that lacks the neural arch ( Fig. 7e-g). Podial elements are represented by a left metacarpal II (MB.Ma. 17146; Fig. 7h-j), a right unciform (MB.Ma. 17147; Fig. 7k-m) and a right astragalus (MB.Ma. 17148; Fig. 7n-o). Recent taxonomic revisions of the South American gomphotheres, based on well-preserved diagnostic materials (e.g., upper tusks and/or complete skull elements), allowed the recognition of only two species, namely Cuvieronius hyodon Fischer, 1814, and Notiomastodon platensis Ameghino, 1888, with a distribution encompassing lowland to highland localities (Lucas, 2013;Mothé et al., 2013;Mothé and Avila, 2015). Some morphological distinctions have been observed in postcranial elements among North American and Neotropical gomphotheres (e.g., Ferretti, 2010;Lucas et al., 2011;Lucas, 2013). However, the lack of more detailed studies in postcranial bones of South American gomphotheres makes the identification of diagnostic features at generic or specific level difficult, especially if the specimens are not associated with other cranial elements such as mandibles, teeth and tusks (e.g., Mothé and Avila, 2015).

Indeterminate mammalian remains
Some specimens are only ascribed to Mammalia indet. due to their fragmentary nature (Figs. 7p-s, 8). They notably include what seems to be a fragment of the femoral head of a gigantic taxon (MB.Ma. 14109; Fig. 7r-s). While its maximum diameter reaches roughly 20 cm, the proximal surface shows an irregular typical structure denoting an unfused epiphysis, indicating that the individual was not skeletally mature.

Implications and significance of Hermann Karsten's vertebrate collection
According to Röhl (1944Röhl ( , p. 1004, the first mention of fossil vertebrate remains found by H. Karsten dates from his exploration to the provinces of Caracas and Carabobo (trips made during his first journey to Venezuela between 1844 and 1847). Röhl (1944Röhl ( , p. 1004 noted that H. Karsten discovered remains of Megatherium in the vicinity of San Juan de Los Morros. In reference to this find, H. Karsten (1849, pp. 198-199) 1851, 1886Nectario María, 1937, 1941Schaub, 1935;Von der Osten, 1951). However, later taxonomic revisions (e.g., Cartelle and Iuliis, 1995) suggest that the previous assignations to Megatherium for specimens found in the region are erroneous, ascribing those specimens to Eremotherium (Cartelle and De Iuliis, 1995). Our own attributions go in the same direction.
In 1847 H. Karsten came back to Germany, and after one year (1848) returned to Venezuela to continue with his explorations; the Academy of Sciences in Berlin provided him with 300 thalers for paleontological excavations (Röhl, 1944). Megatherium remains from Barbacoas, Andes of Lara State (Karsten, 1849, p. 197), Carora (La Mesa, south Baragua River), Lara State (Karsten, 1851, p. 465)  cón State (Karsten, 1851, p. 467), were referred to. Possible "ground sloth" remains were also found by H. Karsten in Cerro Turimiquire, Sucre State, western Venezuela (Karsten, 1859b, p. 292;1886, p. 11 Venezuela and one in Colombia. The Venezuelan location mentioned on the labels is Barbacoas, and we did not find any specimens from the other Venezuelan locations (Carora, Paraguaná Peninsula and Cerro Turimiquire) mentioned by H. Karsten (Karsten, 1851, pp. 465, 467;1859b, p. 292;1886, p. 11). There are no vertebrate specimens labeled as being from the Colombian sites of San José de Cúcuta (Karsten, 1851, p. 467) or El Plato (Karsten, 1886, p. 49). The only specimens from Colombia in the H. Karsten collection are those labeled as from "Barbacoas-Candelillas District, Kolumbien" (Table 2). We did not find a mention of the latter location in any of the relevant publications (Karsten, 1853(Karsten, , 1858(Karsten, , 1859a(Karsten, , 1886, and, as mentioned above, "Barbacoas-Candelillas District" may have been part of the former province of Barbacoas, which existed from 1846 to 1855, in the Republic of New Granada (nowadays Nariño Department, southern Colombia). Although it is unknown whether H. Karsten visited this location, it is recorded that on his trip he visited many places in its vicinity (e.g., Karsten, 1886, pp. 1-2, 22-35). Karsten (1886, p. 49) stated about his fossil vertebrate find from Colombia "toutes les peines que je pris pour en déterrer quelques-uns des mieux conservés, dans un but scientifique, furent rendues vaines par la fragilité des ossements; je ne dressai pas même de liste exacte de ces localités, tant elles étaient nombreuses, de sorte que je ne puis malheureusement donner maintenant qu'une partie de celles que j'ai connues". Due to the unclear information in H. Karsten's publications and in the catalog data, it is not possible to establish with certainty the provenance of many fossil vertebrates. After more than 160 years, problems associated with labels/classification and/or destruction and damage of collections, especially during the Second World War, could have affected valuable information and even the final whereabouts of some "missing" H. Karsten fossils. It is possible that H. Karsten did not collect all the fossil vertebrates he referred to, as was noted by himself (e.g., Karsten, 1886, p. 49). Many historical and geological/paleontological publications, especially about Venezuela, have mentioned H. Karsten's fossil vertebrate finds in a repetitive manner and sometimes with incorrect taxonomic and provenance information (e.g., Jahn, 1921, p. 39;Liddle, 1928, p. 351;Schaub, 1935, p.1;Von der Osten, 1947, p. 161;Takacs et al., 1967Takacs et al., or 1968Linares, 1983, p. 1;Ochsenius, 1980, p. 21;Rincón et al., 2006Rincón et al., , p. 530, 2008Rincón and White, 2007, p. 2;Carrillo-Briceño et al., 2008, p. 242;Rincón, 2011, p. 894). In a detailed revision of H. Karsten's bibliography (e.g., Karsten, 1849Karsten, , 1850aKarsten, , b, 1851Karsten, , 1862, 1886), we have not been able to find any mention of or reference to fossil remains of glyptodonts, toxodonts, proboscideans or horses, from Barbacoas (Lara State) or any other locality of Colombia or Venezuela, contrary to reports by Jahn (1921, p. 39), Liddle (1928, p. 351), Schaub (1935, p. 1), Von der Osten (1947, p. 161), Takacs et al. (1967, p. 32), Linares (1983, p. 1), Ochsenius (1980, p. 21), Rincón et al. (2006Rincón et al. ( , p. 530, 2008, Rincón and White (2007, p. 2), Carrillo-Briceño et al. (2008, p. 242), and Rincón (2011, p. 894). For example, Jahn (1921, p. 39) stated "En las arcillas sedimentarias de Barbacoas descubrió Karsten en 1850 restos fósiles de Taxodon [sic], Gliptodon [sic], Mastodon y una especie de equino que se diferencia bastante, en cuanto a su dentadura, del Equus Andium [sic] del Ecuador". The reference of Jahn (1921, p. 39) has possibly given rise to the use of this erroneous information in a repetitive manner by Liddle (1928, p.351) and other subsequent publications. The new taxonomic list presented herein securely documents the existence of "South American ungulates", "ground sloths", glyptodonts and proboscidean remains in the H. Karsten collection (MB.Ma.); however, their provenance is unclear. The H. Karsten vertebrate collection lacks a clear stratigraphic/age context; nevertheless, none of the specimens are well mineralized, having a typical Pleistocene type of preservation. From the overall H. Karsten vertebrate collection, the "ground sloth" remains are the most abundant. As is to be expected, the widely distributed species Eremotherium laurillardi (Cartelle and De Iuliis, 1995) is represented in the collection. The rest of the "ground sloths," together with the Toxodontidae and Gomphotheriidae specimens, do not offer significant information regarding biostratigraphy and biogeography, due to the fragmentary nature and scarce diagnostic characters of the specimens. In contrast, the presence of Glyptotherium cf. G. cylindricum from San Juan de Los Morros (Orinoco River basin) increases the paleobiogeographic range of this taxon because to date Glyptotherium remains have only been recorded in South America in a few lowland Late Pleistocene localities of the Caribbean basin in Venezuela (Carlini et al., 2008;Carlini and Zurita, 2010) and the Atlantic coast of Brazil up to 20 • S (Oliveira et al., 2010). According to Zurita et al. (2012), Glyptotherium records from Venezuela and Brazil suggest that after its entry into South America during the Great American Biotic Interchange (GABI), this taxon could have followed an "eastern corridor" as a migratory route. Below the 20 • S, the only recorded Glyptodontinae corresponds to Glyptodon, which is also recorded in a strip parallel to the Cordillera de Los Andes (Zurita et al., 2012).

Conclusions
Hermann Karsten is well known due to his various contributions to botany in South America during the second part of the 19th Century. His explorations allowed him to produce important geographic and geologic descriptions that make him a pioneer in these topics as well. Although the H. Karsten collections from South America are found in different museums and botanical gardens of Europe (e.g., extant plants and some fossil invertebrates), we have not found references to vertebrate fossil specimens deposited in any other collection apart from the Museum of Natural History Foss. Rec., 20, 21-36, 2016 www.foss-rec.net/20/21/2016/ in Berlin. For more than 160 years, this vertebrate collection was practically unknown and subject to incorrect taxonomic and provenance references. Many of H. Karsten's vertebrate fossils are broken and incomplete, which prevented us from undertaking a more accurate taxonomic identification for specimens of Mylodontidae, Toxodontidae and Gomphotheriidae, with the exception of the "ground sloth" Eremotherium laurillardi. However, the identification of Glyptotherium cf. G. cylindricum from San Juan de Los Morros (Orinoco River basin) increases the paleobiogeographic range of this taxon, which has been previously referred to from a few coastal locations in Venezuela and Brazil. Using H. Karsten's publications and his fossil collection, we can suggest that fossil remains attributable to horses were not found by him during his expeditions, contrary to claims in many publications from the 19th and 20th century. The H. Karsten vertebrate collection was one of the first made during a scientific exploration in Venezuela and the Nueva Granada and is thus of historical importance for the paleontology of the region.

Data availability
The data presented are based purely on fossil specimens, which are designated by a specific catalog number. All the fossil specimens used here are available in their entirety in a public repository: the fossil vertebrate collection of the Museum für Naturkunde in Berlin (MB.Ma.). Access to the collection is obtained by a request directly to the curator of the collection and the relevant authorities. All relevant data necessary to replicate the results presented in our article are available in this paleontological collection.