First fossil small-clawed otter, <i>Amblonyx</i>, with a note on some specimens of <i>Lutra</i>, from the Upper Siwaliks, India

Abstract

Otter-like mammals have been reported from the Indian sub-continent for more than a century and a half. Enhydriodontini are far more common and have a longer fossil record than either Lutrini or Aonychini. This paper describes and interprets two fossils from the Pleistocene of Panchkula and Pipalwala, India. The Panchkula specimen represents a large species of Amblonyx (Aonychini) whereas the Pipalwala specimen is likely to represent a large individual of Lutra palaeindica (Lutrini).Key words: Otters, Amblonyx, Lutra, Pleistocene, India, Siwaliks, new species. RESUMENMamíferos de tipo nutria han sido señalados en el subcontinente Indio desde hace más de un siglo y medio. Los Enhydriodontini son de lejos los más comunes y tienen un mayor registro fósil que los Lutrini o los Aonychini. En este trabajo describimos e interpretamos dos fósiles procedentes del Pleistoceno de Panchkula y Pipalwala, India. El ejemplar de Panchkula representa una especie de talla grande de Amblonyx (Aonychini), mientras que el ejemplar de Pipalwala representa a un individuo de talla grade de Lutra paleoindica (Lutrini).

Rediscovering Lutra lutra from Grotta Romanelli (southern Italy) in the framework of the puzzling evolutionary history of Eurasian otter

“…Body size in extant otters is hugely variable, reflecting the diverse ecological niches this group occupies (Conroy et al 2000;Kruuk 2006): small-sized piscivore (c. 5-10 kg), medium-sized cancrivore (c. 11-12 kg) and large-sized molluscivore (c. 22-25 kg) (Raghavan et al 2007). Therefore, in the fossil record, reconstructing the body size could represent an important proxy to evaluate possible ecological niche differentiation (Conroy et al 2000).…”

“…However, the latter taxon is only known from the type sample (Falconer 1868;Fig. 3 Plot of lower carnassial: a length of M 1 vs. width of M 1 talonid; b length of M 1 vs. width of M 1 W index (calculated as M 1 W talonid−M 1 W trigonid) Pohle 1919;Mattthew 1929), and possibly from another specimen (Raghavan et al 2007), recovered from the Upper Siwalik. Similarly, no cranial material of L. simplicidens has been described so far, which highlights the strongly restricted knowledge on the morphological variability of these species.…”

“…In fact, given its robust dentition with broader teeth, several authors aligned it with Aonyx (e.g., Malatesta 1978;Pennacchioni and Cassola 1986), whose paleobiological interpretation points to a more important role of shellfish in its diet (Willemsen 1992). Following this, a sympatric coexistence scenario of the fish-feeding L. simplicidens and L. lutra with C. antiqua could be possible, with different craniodental features which reflect the Raghavan et al (2007) 11.5 Lutra lutra Hoxne BM4936 Willemsen (1992) 12.3 Cyrnaonyx antiqua Tornewton Cave BM M 34370 Willemsen (1992) 11.2 Cyrnaonyx antiqua Tornewton Cave BM M 34373 Willemsen (1992) 11.3 Cyrnaonyx antiqua Tornewton Cave BM M 34374 Willemsen (1992) 11.6 Cyrnaonyx antiqua Tornewton Cave BM M 50707 Willemsen (1992) 11.0 Cyrnaonyx antiqua Verona M7 Willemsen (1992) 11.8 diversification of ecological niches. The other fossil European otter, Lutraeximia umbra, according to Cherin et al (2016) had a strong preference for hard prey (molluscs), but possessed intermediate features between fish specialist and hard invertebrates dentition.…”

“…The latter taxon is only known from the holotype cranium, whereas the former is relatively widespread in the early Middle Pleistocene and is regarded as ancestral to several endemic otters of the Mediterranean islands (Willemsen 2006): "Lutra" euxena from Malta, Lutraeximia trinacriae from Sicily, and Sardolutra ichnusae, "Lutra" castiglionis, Algarolutra majori and Megalenhydris barbaricina from Sardinia and Corsica, even though these fossil samples often include few and fragmentary remains (Willemsen 1992;Cherin et al 2016). Nonetheless, the extant Eurasian river otter, Lutra lutra, is considered not related to these European species and its origin is placed in the Asian continent, probably deriving from the fossil species Lutra palaeoindica (Willemsen 1992;Raghavan et al 2007). This scenario has received indirect support from the first description of L. simplicidens maxillary dentition, which led Cherin (2017) to doubt of the species generic attribution, remarking the similarities with Lutraeximia umbra (Cherin et al 2016).…”