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1

The dental evidence on the differentiation of the ctenomyine rodents [Caviomorpha, Octodontidae, Ctenomyinae]

100%

Verzi D. H.

Acta Theriologica

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1999

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tom 44

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nr 3

EN

Primitive species in the differentiation of the subfamily Ctenomyinae are revisited, and, on molar evidence, a new interpretation of the evolutionary pattern of these earliest members of the group is proposed. The octodontid Phtoramys is rejected as possible ancestor, whereas the genus Chasichimys (including Pattersomys), previously included in the family Echimyidae, is transferred to the Octodontidae as a primitive member of the ctenomyine radiation. During the Chasicoan and Huayquerian Ages [Late Miocene), an anagenetic event represented by an increase of hypsodonty in Chasichimys, may have led to the differentiation of the primitive euhypsodont ctenomyines of the genus Xenodontomys. Coeval cladogenetic processes, occurring during the protohypsodont evolutionary stage of the group, would have resulted in the separation of the genus Palaeoctodon from the lineage Chasichimys-Xenodontomys. These ancient representatives of the subfamily would have differentiated in central Argentine pampas. The recognition of such evolutionary events and concordant evidence from other octodontoid rodents suggest temporal differences among the outcroppings of the Cerro Azul Formation in central Argentina.

2

Phylogenetic position of Abalosia and the evolution of the extant Octodontinae [Rodentia, Caviomorpha, Octodontidae]

100%

Verzi D. H.

Acta Theriologica

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2001

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tom 46

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nr 3

EN

South American octodontid rodents of the subfamily Octodontinae currently show low species richness but great morphological and chromosomal diversity. This diversity is interpreted alternatively as the remnant of a wider past radiation or as the result of saltational evolution. These hypotheses are discussed in relation to a phylogenetic analysis of the Late Pliocene octodontine Abalosia castellanosi. My results suggest that Abalosia, together with Tympanoctomys and Octomys, is part of a clade of desert specialist propalinal octodontids, which would have differentiated east of the Andes in the emergent semi-deserts of western Argentina. The presence of Abalosia in the coastal region of central Argentina during the Upper Marplatan Age (Late Pliocene) suggests a pulse of expansion of such arid environments, probably coeval with the global climatic deterioration detected around the transition Gauss-Matuyama magnetic ages. The phylogenetic position of A. castellanosi suggests that extinction events affected the clade of the octodontine desert specialists. Accordingly, regardless of how rough or gradual the differentiation of the octodontine's diversity has been, the living representatives seem to be remnants of a wider radiation.

3

A new early Pliocene murine rodent from the Iberian Peninsula and its biostratigraphic implications

63%

Pinero P. , Verzi D. H.

Acta Palaeontologica Polonica

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2020

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tom 65

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nr 4

4

Phylogeny and evolutionary patterns of South American octodontoid rodents

51%

Verzi D. H. , Olivares A. I. , Morgan C. C.

Acta Palaeontologica Polonica

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2014

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tom 59

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nr 4

EN

Octodontoidea is the most diverse clade of hystricognath rodents, and is richly recorded in South America since at least the Oligocene. A parsimony-based morphological phylogenetic analysis of a wide range of extant and extinct octodontoids recovered three major clades, here recognised as Echimyidae, Octodontidae, and Abrocomidae. Taxa previously assigned to Echimyidae or Octodontoidea incertae sedis are here interpreted for the first time as early representatives of Ctenomyinae (Octodontidae), Octodontinae or Abrocomidae. Based on our results, we estimate the divergence of octodontoid families and subfamilies to have occurred during the Late Oligocene, which is consistent with molecular estimates, but older than previous inferences based on the fossil record. Contrary to previous suggestions, we show the first appearances of modern members of Abrocomidae, Octodontinae and Ctenomyinae to be distinctly decoupled from the origin of these clades, with different stages in the evolutionary history of octodontoids seemingly following distinct phases of palaeoenvironmental change. Depending on the phylogenetic pattern, fossils from the stage of differentiation bear evolutionary information that may not be provided by crown groups, thus highlighting the unique and important contribution of fossils to our understanding of macroevolutionary patterns.

5

The fishing bat Noctilio (Mammalia, Chiroptera) in the Middle Pleistocene of central Argentina

51%

Merino M. L. , Lutz M. A. , Verzi D. H. , Tonni E. P.

Acta Chiropterologica

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2007

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tom 09

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nr 2

EN

We report the record of a canine tooth assignable to an undetermined species of Noctilio from the Middle Pleistocene of the Atlantic coast in central Argentina. This is the southernmost record for the genus and the first paleontological record of Noctilio in southern South America. In addition, this finding supports the hypothesis of an episodic warm climatic pulse suggested by other micromammals recovered from the same fossil-bearing levels.