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Bajpai, Sunil; Domning, Daryl Paul; Das, Debi P.; Vélez-Juarbe, Jorge; Mishra, Vijay P.
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2010 |
A new fossil sirenian (Mammalia, Dugonginae) from the Miocene of India.
Neues Jb. Geol. Pal. Abh. 258(1): 39-50. 3 tabs. 6 figs. Published online June 2010.
–Describes Kutchisiren cylindrica, n.gen.n.sp., from the Lower Miocene (Aquitanian or Burdigalian) Khari Nadi Formation of Kutch, Gujarat, western India.
urn:lsid:zoobank.org:pub:B3B87E4E-AC64-44C4-8D49-69699BF123DF
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Vélez-Juarbe, Jorge; Domning, Daryl Paul; Pyenson, Nicholas D.
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2012 |
Iterative evolution of sympatric seacow (Dugongidae, Sirenia) assemblages during the past ~26 million years.
PLoS ONE 7(2): e31294. 8 pp. 1 tab. 3 figs. + 1 fig. in Supporting Information. DOI:10.1371/journal.pone.0031294. Feb. 3, 2012.
–Available online at: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0031294.
ABSTRACT: Extant sirenians show allopatric distributions throughout most of their range. However, their fossil record shows evidence of multispecies communities throughout most of the past ~26 million years, in different oceanic basins. Morphological differences among co-occurring sirenian taxa suggest that resource partitioning played a role in structuring these communities. We examined body size and ecomorphological differences (e.g., rostral deflection and tusk morphology) among sirenian assemblages from the late Oligocene of Florida, early Miocene of India and early Pliocene of Mexico; each with three species of the family Dugongidae. Although overlapping in several ecomorphological traits, each assemblage showed at least one dominant trait in which coexisting species differed. Fossil sirenian occurrences occasionally are monotypic, but the assemblages analyzed herein show iterative evolution of multispecies communities, a phenomenon unparalleled in extant sirenian ecology. As primary consumers of seagrasses, these communities likely had a strong impact on past seagrass ecology and diversity, although the sparse fossil record of seagrasses limits direct comparisons. Nonetheless, our results provide robust support for previous suggestions that some sirenians in these extinct assemblages served as keystone species, controlling the dominance of climax seagrass species, permitting more taxonomically diverse seagrass beds (and sirenian communities) than many of those observed today.
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Vélez-Juarbe, Jorge
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2014 |
Ghost of seagrasses past: using sirenians as a proxy for historical distribution of seagrasses.
Palaeogeogr. Palaeoclim. Palaeoecol. 400: 41-49. 1 tab. 4 figs. http://dx.doi.org/10.1016/j.palaeo.2013.05.012 Apr. 15, 2014.
–ABSTRACT: Seagrasses are a notable component of shallow marine habitats, especially in tropical and subtropical regions. Their fossil record extends back to the Mesozoic, but it is relatively poor and fragmentary, with large temporal and geographical gaps. As a result, very little is known about the paleobiogeography of these plants and how physical drivers, such as climatic or oceanic events, have affected their distribution. One approach is to infer the past distribution of seagrasses using fossils of organisms dependent of seagrasses with more complete records as proxies.
Seagrass consumers, such as sirenians (seacows, manatees and dugongs), are much better represented in the fossil record than seagrasses are. The characteristically dense bones of sirenians together with the fact that they are usually found in marginal marine environments increases the potential for preservation and recognition of their fossils. The long evolutionary history of sirenians, extending throughout most of the last 50 Ma, together with their diet permits the use of their fossils as a proxy for inferring the paleobiogeography of seagrasses.
Here I looked at the fossil record of sirenians and seagrasses from the Eocene, through the Miocene epochs. This comparison produced several inferences about seagrass paleobiogeography and how physical drivers, such as climate change, ocean currents and tectonic events, have been influential in their distribution: 1) seagrasses were well-established in the Western Atlantic–Caribbean prior to the middle Eocene, making possible at least two instances of trans-Atlantic sirenian dispersal events, either with the aid of Tethyan currents or along the nearly continuous Northern Atlantic coastline that was present in the Eocene; 2) climatic cooling during the early Oligocene seemed to have limited the extent of seagrasses and sirenians, although these groups recovered and further diversified and expanded their distributions by the late Oligocene in tandem with a climatic warming event; 3) by the Miocene, seagrasses and sirenians reached the southern Western Atlantic and the Eastern Pacific aided by the presence of the Central American Seaway, achieving a distribution similar to, and sometimes, surpassing that of today. The fossil record of sirenians can provide a broad overview of seagrass paleobiogeography through time. However, several aspects, such as when sirenians and seagrasses arrived to Australia and the seemingly late arrival of seagrasses to South America and the Eastern Pacific, still need further investigation.
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Vélez-Juarbe, Jorge; Domning, Daryl Paul
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2014a |
Fossil Sirenia of the West Atlantic and Caribbean region. IX. Metaxytherium albifontanum, sp. nov.
Journal of Vertebrate Paleontology 34(2): 444-464. 11 tabs. 15 figs. + supplemental online material. http://www.tandfonline.com/doi/abs/10.1080/02724634.2013.799072 Mar. 2014 (publ. online Mar. 4, 2014).
–ABSTRACT: We describe a new species of the halitheriine dugongid genus Metaxytherium from the late Oligocene of Florida and South Carolina. The new species is represented by cranial and postcranial material, including parts of the axial and appendicular skeleton. Metaxytherium albifontanum, sp. nov., differs from other species of Metaxytherium by the following unique combination of plesiomorphic and derived characters: posterior end of nasal process of premaxilla broad and flat relative to what is observed in most other members of the genus (somewhat resembling M. subapenninum); ventral extremity of jugal under posterior edge of orbit (character 85[1]) (shared with M. krahuletzi); exoccipitals separated in dorsal midline (character 66[1]) (shared with all other species in the genus, except some M. krahuletzi); and innominate with acetabulum (nearly lost or lost in M. crataegense, M. floridanum, M. serresii). This new species was sympatric with two dugongines, Crenatosiren olseni and Dioplotherium manigaulti. The small tusks and cranial morphology of M. albifontanum, sp. nov., indicate that it was likely a consumer of small seagrasses. Our phylogenetic analysis is consistent with previous ones in placing Hydrodamalinae within a paraphyletic Metaxytherium spp. and placing the Metaxytherium spp. + Hydrodamalinae clade as the sister group to Dugonginae. Metaxytherium albifontanum, sp. nov., is the oldest known member of its genus; this might indicate that the group originated in the West Atlantic and Caribbean region and later dispersed to the Old World Tethys region.
urn:lsid:zoobank.org:pub:7BFB3FB9-5622-4696-A1AA-8220FA2A12A5
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Vélez-Juarbe, Jorge; Domning, Daryl Paul
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2014b |
Fossil Sirenia of the West Atlantic and Caribbean region: X. Priscosiren atlantica, gen. et sp. nov.
Journal of Vertebrate Paleontology 34(4): 951-964. 4 tabs. 9 figs. July 2014 (publ. online July 8, 2014).
–ABSTRACT: We describe a new genus and species of early Oligocene halitheriine dugongid from the Western Atlantic region. Priscosiren atlantica, gen. et sp. nov., differs from all other halitheriine dugongids by displaying the following unique combination of characters: supraorbital processes dorsoventrally thin (?1 cm) with well-developed prominent posterolateral corner; supraoccipitals wider in the dorsal half than the ventral half; exoccipitals meeting dorsal to the foramen magnum; posttympanic process with a prominent anteroventral process for attachment of m. sternomastoideus; nasals separated in midline; ventral extremity of jugal located ventral to orbit; ventral border of mandible strongly concave; absence of accessory mental foramina; dorsoventrally broad horizontal ramus of mandible; loss of all permanent premolars; and concave anteroventral surface of jugal (a possible autapomorphy). Differs further from the similar species Caribosiren turneri in having lesser rostral deflection (of about 44°); presence of small incisors; lower temporal crests; and slightly larger body size. The relationship of Priscosiren with other dugongids places it close to being a structural as well as temporal ancestor to the Metaxytherium + Hydrodamalinae and Dugonginae clades. This supports previous assumptions of a Western Atlantic and Caribbean origin for these groups, and indicates that the halitheriine-dugongine divergence must have occurred no later than the earliest Oligocene. Priscosiren, Caribosiren, and Crenatosiren evidently coexisted in the West Atlantic–Caribbean region, and constitute yet another case of a uniquely patterned fossil sirenian multispecies community.
urn:lsid:zoobank.org:pub:D465CBCE-19AE-4E1D-A4EE-84443896C13B
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Springer, Mark S.; Signore, Anthony V.; Paijmans, Johanna L. A.; Vélez-Juarbe, Jorge; Domning, Daryl Paul; Bauer, Cameron E.; He, Kai; Crerar, Lorelei D.; Campos, Paula F.; Murphy, William J.; Meredith, Robert W.; Gatesy, John; Willerslev, Eske; MacPhee, Ross D. E.; Hofreiter, Michael; Campbell, Kevin L.
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2015 |
Interordinal gene capture, the phylogenetic position of Steller's sea cow based on molecular and morphological data, and the macroevolutionary history of Sirenia.
Molecular Phylogenetics & Evolution 91: 178-193. 5 tabs. 5 figs. 9 tabs. in online Supplementary Material. DOI:10.1016/j.ympev.2015.05.022 Publ. online June 4, 2015.
–ABSTRACT: The recently extinct (ca. 1768) Steller's sea cow (Hydrodamalis gigas) was a large, edentulous North Pacific sirenian. The phylogenetic affinities of this taxon to other members of this clade, living and extinct, are uncertain based on previous morphological and molecular studies. We employed hybridization capture methods and second generation sequencing technology to obtain >30 kb of exon sequences from 26 nuclear genes for both H. gigas and Dugong dugon. We also obtained complete coding sequences for the tooth-related enamelin (ENAM) gene. Hybridization probes designed using dugong and manatee sequences were both highly effective in retrieving sequences from H. gigas (mean = 98.8% coverage), as were more divergent probes for regions of ENAM (99.0% coverage) that were designed exclusively from a proboscidean (African elephant) and a hyracoid (Cape hyrax). New sequences were combined with available sequences for representatives of all other afrotherian orders. We also expanded a previously published morphological matrix for living and fossil Sirenia by adding both new taxa and nine new postcranial characters. Maximum likelihood and parsimony analyses of the molecular data provide robust support for an association of H. gigas and D. dugon to the exclusion of living trichechids (manatees). Parsimony analyses of the morphological data also support the inclusion of H. gigas in Dugongidae with D. dugon and fossil dugongids. Timetree analyses based on calibration density approaches with hard- and soft-bounded constraints suggest that H. gigas and D. dugon diverged in the Oligocene and that crown sirenians last shared a common ancestor in the Eocene. The coding sequence for the ENAM gene in H. gigas does not contain frameshift mutations or stop codons, but there is a transversion mutation (AG to CG) in the acceptor splice site of intron 2. This disruption in the edentulous Steller's sea cow is consistent with previous studies that have documented inactivating mutations in tooth-specific loci of a variety of edentulous and enamelless vertebrates including birds, turtles, aardvarks, pangolins, xenarthrans, and baleen whales. Further, branch-site dN/dS analyses provide evidence for positive selection in ENAM on the stem dugongid branch where extensive tooth reduction occurred, followed by neutral evolution on the Hydrodamalis branch. Finally, we present a synthetic evolutionary tree for living and fossil sirenians showing several key innovations in the history of this clade including character state changes that parallel those that occurred in the evolutionary history of cetaceans.
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Vélez-Juarbe, Jorge; Domning, Daryl Paul
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2015 |
Fossil Sirenia of the West Atlantic and Caribbean region. XI. Callistosiren boriquensis, gen. et sp. nov.
Journal of Vertebrate Paleontology 35(1): e885034 (16 pp.). 4 tabs. 11 figs. DOI: 10.1080/02724634.2014.885034 Jan. 2015 (publ. online Jan. 26, 2015).
–Spanish summ.
ABSTRACT: Here we describe a new taxon of late Oligocene dugongine from the Western Atlantic and Caribbean region. Known from cranial and postcranial material, Callistosiren boriquensis, gen. et sp. nov., differs from other members of the group by displaying the following unique combination of characters: nasal process of premaxilla tapering but thickened; supraorbital process of frontal dorsoventrally thin (<2 cm) and well developed with recurved, bluntly pointed posterolateral corner; ventral rim of orbit not overhanging the lateral surface of the jugal; pterygoid fossa tall; tusks large, lozenge- or kite-shaped in cross-section, and with enamel confined to the medial side; lacrimals with thin, elongated dorsal process that is wedged between the premaxilla and frontal; and osteosclerotic but minimally pachyostotic ribs and vertebrae. A phylogenetic analysis places Callistosiren as one of the more basal members of the Dugonginae, but we note that the relationships and taxonomy of more derived members are in need of revision. Characters of the cranial morphology, such as the shape and size of the incisor tusks and the nature of the contact between the premaxilla and frontal, indicate that this new taxon may have fed preferentially on large species of seagrasses and their rhizomes. In addition, possession of osteosclerotic but minimally pachyostotic ribs and vertebrae is a unique feature unknown in other extinct dugongines and may indicate foraging behavior not known from other fossil sirenians.
urn:lsid:zoobank.org:pub:E3FF5EB3-B54F-44DF-9528-FE9E2A353356
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Antoine, P.-O.; Abello, M. A.; Adnet, S.; Altamirano Sierra, A. J.; Baby, P.; Billet, G.; Boivin, M.; Calderón, Y.; Candela, A.; Chabain,J.; Corfu, F.; Croft, D. A.; Ganerød, M.; Jaramillo, C.; Klaus, S.; Marivaux, L.; Navarrete, R. E.; Orliac, M. J.; Parra, F.; Pérez, M. E.; Pujos, F.; Rage, J.-C.; Ravel, A.; Robinet, C.; Roddaz, M.; Tejada-Lara, J. V.; Vélez-Juarbe, Jorge; Wesselingh, F. P.; Salas-Gismondi, R.
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2016 |
A 60-million-year Cenozoic history of western Amazonian ecosystems in Contamana, eastern Peru.
Gondwana Research 31: 30-59.
–Early Mioc. record of Trichechinae in South America.
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Pyenson, Nicholas D.; Parham, James F.; Vélez-Juarbe, Jorge
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2016 |
The dilemma of trade samples and the importance of museum vouchers – caveats from a study on the extinction of Steller's sea cow: a comment on Crerar et al. (2014).
Biology Letters (Royal Society) 12: 20150149; 2 pp. http://dx.doi.org/10.1098/rsbl.2015.0149 Feb. 3, 2016.
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Vélez-Juarbe, Jorge; Wood, Aaron R.
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2019 |
An early Miocene dugongine (Sirenia: Dugongidae) from Panama.
Jour. Vert. Paleo. 38(5): e1511799 (16 pp.). 4 tabs. 8 figs. https://doi.org/10.1080/02724634.2018.1511799. "Sept. 2018"; publ. online Feb. 15, 2019.
–ABSTRACT: Herein, we describe a new early Miocene dugongine from marine deposits of the Culebra Cut (Gaillard Cut) of the Panama Canal. The new taxon, Culebratherium alemani, gen. et sp. nov., represents one of the few records of late Aquitanian–early Burdigalian sirenians and the oldest sirenian from Central America. A phylogenetic analysis places Culebratherium in a clade with Dioplotherium cf. D. allisoni (Miocene of Brazil), Dioplotherium allisoni (Miocene of Baja California Sur, Mexico, and California, U.S.A.), and Dioplotherium sp. (Pliocene of Yucatan, Mexico). Similar to these taxa, Culebratherium is characterized by the presence of large incisor tusks, a premaxillary symphysis without a boss, a premaxilla-frontal suture forming a butt joint, and a moderately downturned rostrum. In addition, Culebratherium exhibits prominent occipital-cervical attachment sites for enlarged neck musculature. These features taken together are interpreted as adaptations for uprooting large, deeply buried seagrass rhizomes. Other dugongines with similar, yet convergent, dental and facial adaptations are known from earlier or coeval deposits in Puerto Rico, Florida, South Carolina, California, Baja California Sur, Brazil, and India and were constituents of sympatric paleocommunities of sirenians. Only fragmentary evidence of a second smaller and unidentifiable sirenian species is known from the Culebra Formation, but future discoveries may reveal a similar sympatric paleocommunity during the early Miocene of Panama. Finally, we used the results of the phylogenetic analysis to propose the new clade Pan-Sirenia as the most inclusive group consisting of stem and crown groups and redefine the Sirenia, Dugongidae, and Dugonginae clades.
["Pan-Sirenia" was previously defined by O'Leary et al., 2013.]
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Suarez, Catalina; Gelfo, Javier N.; Moreno-Bernal, Jorge W.; Velez-Juarbe, Jorge
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2021 |
An early Miocene manatee from Colombia and the initial Sirenian invasion of freshwater ecosystems.
Journal of South American Earth Sciences 109: 103277. 1 tab. 5 figs. Supplementary data at https://doi. org/10.1016/j.jsames.2021.10327 Publ. online Mar. 24, 2021.
–ABSTRACT: Potamosiren magdalenensis Reinhart, is an extinct species of manatee (Sirenia, Trichechidae, Trichechinae), which has only been recorded for the middle Miocene Honda Group, in the La Venta area (Huila Department, Colombia). A new specimen referable to Potamosiren cf. P. magdalenensis is reported herein, collected from the early Miocene Barzalosa Formation. This unit crops out in the Pubenza locality, at the Tocaima municipality of the Cundinamarca Department, Colombia. The material described here represents the first evidence of a mammal from the Barzalosa Formation, the earliest record of Potamosiren so far reported and one of the only two trichechid records for the early Miocene of South America. The new specimen adds to a small but growing record of extinct trichechids, increasing the fossil record of this group in South America and allowing us to further explore their evolutionary history. The early Miocene appearance of trichechines coincides geographically and temporally with the onset of the Pebas Mega-Wetland System, which likely provided favourable conditions for the invasion of freshwater ecosystems of this group of fully aquatic mammals. Finally, the depositional environments represented by the Barzalosa Fm. and a review of the fossil record of trichechines further support the notion that manatees have had a close association with freshwater systems since early in their evolutionary history, and that reinvasion of marine ecosystems did not occur until much later.
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Viglino, Mariana; Valenzuela-Toro, Ana M.; Benites-Palomino, Aldo; Hernandez-Cisneros, Atzcalli Ehecatl; Gutstein, Carolina Simon; Aguirre-Fernandez, Gabriel; Velez-Juarbe, Jorge; Cozzuol, Mario A.; Buono, Monica R; Loch, Carolina.
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2023 |
Aquatic mammal fossils in Latin America - a review of records, advances and challenges in research in the last 30 years.
The Latin American Journal of Aquatic Mammals 18(1): 50-66. https://doi.org/10.5597/lajam00295
–ABSTRACT: Records of aquatic mammal fossils (e.g. cetaceans, pinnipeds, sirenians, mustelids, and desmostylians) from Latin America (Mexico to Tierra del Fuego, including Antartica) span since the mid-1800s. Aquatic mammal fossils received little attention from the scientific community, with most of the first studies conducted by Northern Hemisphere researchers. Over the last 30 years, paleontological research in Latin America has increased considerably, with descriptions of several new species and revisions of published original records. The Latin American fossil record of marine mammals spans from the Eocene to the Pleistocene, with formations and specimens of global significance. All three main groups of cetaceans are represented in the continent (Archaeoceti, Mysticeti, and Odontoceti). Pinnipedia are represented by the families Otariidae and Phocidae, with records starting in the Middle Miocene. Both living families of Sirenia (Trichechidae and Dugongidae) are recorded. While less common, but still relevant, records of desmostylians and mustelids are known from Oligocene and Miocene deposits. This review provides a summary of the aquatic mammals known to date, with a special focus on the advances and developments of the last 30 years, since Cozzuol's (1996) review of the South American fossil record. An up-to-date complete list of species based on the literature and unpublished data is also provided. The study also provides future directions for paleontological research in Latin America, and discusses the challenges and opportunities in the field, including the emergence of a strong new generation of Latin American researchers, many of whom are women.
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Benites-Palomino, Aldo; Aguirre-Fernandez, Gabriel; Velez-Juarbe, Jorge; Carrillo-Briceno, Jorge D.; Sanchez, Rodolfo; Sanchez-Villagra, Marcelo R.
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2024 |
Trophic interactions of sharks and crocodylians with a sea cow (Sirenia) from the Miocene of Venezuela.
Journal of Vertebrate Paleontology 43(6): e2381505 (6 pp.) 2 figs. https://doi.org/10.1080/02724634.2024.2381505 Nov. 2023. (Published online: 28 Aug 2024).
–ABSTRACT: Evidence of trophic interactions are not scarce in the fossil record, yet these are mostly represented by fragmentary fossils exhibiting marks of ambiguous significance. Differentiating between marks of active predation and scavenging events is therefore often challenging. Here, we report on a dugongine sea cow skeleton (partial skull and vertebrae) from the Lower to Middle Miocene Agua Clara Formation (Venezuela) with shark and crocodylian bite marks. The sirenian is identified as Culebratherium sp. and preserves crocodylian bite marks across the skeleton. The most conspicuous correspond to deep tooth impacts with dragging effect, concentrated in the rostrum of the specimen. We interpret these as the result of active predation because of the similarity with those produced when a crocodylian holds or rolls a prey. Additionally, shark bite marks can be observed throughout the skeleton, also evidenced by the finding of an isolated tiger shark (Galeocerdo aduncus) tooth associated with this skeleton. Because of the irregular distribution of the shark bite marks, these are interpreted as scavenging. Overall, these findings constitute one of the few records documenting multiple predators over a single prey, and as such provide a glimpse of the trophic networks during the Miocene in the region.
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Bibliography and Index of the Sirenia and Desmostylia 