Cleopatra M. Loza, Oliver Reutimann, Marcelo R. Sánchez-Villagra, Alfredo A. Carlini and Gabriel Aguirre-Fernández
Edited by A. van der Geer
The systematic value of the middle-ear ossicles, in particular the malleus, has been long recognized for diverse groups. We present systematic work on the characters of the middle-ear ossicles of pinnipeds, focusing on until now poorly studied Southern Hemisphere species. Mallei were extracted from 16 specimens of pinnipeds belonging to five austral and one boreal species of Phocidae and two austral species of Otariidae. Several characters used in this study have been described previously, and some were here modified. Three new characters are here defined and analysed. All characters were mapped onto the phylogeny. Our character analysis shows the transformations that have occurred in the evolution of middle ear ossicles in pinnipeds and identifies diagnostic features of many of its clades. Beyond the identification of specific changes within eachclade, our study of pinniped ossicle evolution documents the occurrence of anatomical convergences with other groups of mammals that live in an aquatic environment, as has occurred in other organ systems as well.
Ondřej Korábek, Lucie Juřičková, Igor Balashov and Adam Petrusek
Edited by T. de Winter
Helix lucorum is a large synanthropic land snail of substantial economic importance, which has been recently reported from a number of new sites in Western, Central, and Eastern Europe. It is an originally Anatolian and Caucasian species, but its presumed natural distribution also covers the south and east of the Balkans. Populations of unclear origin, known as Helix lucorum taurica, live in the south-western part of Crimea. The Balkan and Crimean populations differ in their appearance, were long treated as different species or subspecies, and the Crimean populations are protected by law as a presumably endemic taxon. Here we explore the origins of European populations using phylogenetic analysis of mitochondrial markers. The results point to north-eastern Anatolia and the Lesser Caucasus as the centre of H. lucorum diversification. The Crimean conchological form, along with the associated mitochondrial lineage, is not endemic to that peninsula and was likely introduced there. Other European samples belong to a different lineage, which is associated with the nominotypical conchological form of H. lucorum. The conchological characteristics of the nominotypical form are unusual within the genus Helix, and we propose this reflects a change in habitat use and parallels the evolution of some other lineages of Helicidae. As a result, the typical European H. lucorum differs considerably from the Crimean populations, but the two lineages just represent opposite ends of a continuum in conchological characteristics. Their formal descriptions were based on probably introduced populations detached from the main range. Separated from the geographic pattern of the overall variation of H. lucorum they appeared distinctive, thus confounding the taxonomy of the species. Currently, the division of H. lucorum into subspecies appears unwarranted. Helix lucorum may not be a unique example of a large snail successfully expanding from Anatolia, as we argue that even the native origin of Balkan populations is uncertain. However, further sampling in north-western Turkey and analysis of archaeozoological findings from the south-eastern Balkans is needed to evaluate this hypothesis.
Denis Audo, Matúš Hyžný and Sylvain Charbonnier
Edited by R. Vonk
Polychelidan lobsters, as the sister group of Eureptantia (other lobsters and crabs), have a key-position within decapod crustaceans. Their evolutionary history is still poorly understood, although it has been proposed that their Mesozoic representatives largely inhabited shallow-marine environment and only later sought refuge in deep water. This view has recently been challenged, so the evolutionary history of polychelidans is in a need of re-appraisal. The earliest representatives, such as Tetrachela from the Late Triassic of Austria and Italy, are of great importance because of their potential in investigation of life habits of early polychelidans. Tetrachela lived in a relatively deep water, however, its well-developed eyes suggest an environment where light was still present. With its massive dorsoventrally flattened body plan, Tetrachela was probably benthic; the shape of its mandible and stocky first pereiopods suggest it was a scavenger and/or fed on slowly moving or sedentary animals. The carapace of Tetrachela has a peculiar groove pattern, which leads us to redefine some elements of the nomenclature of grooves used for polychelidans. Based on the present revision we propose that the second incision and its associated groove correspond to the hepatic groove, not the postcervical or the branchiocardiac grooves as interpreted previously. This revision allows us to review the homologies of cephalothoracic groove between polychelidans and other notable groups of decapod crustaceans.
Collecting, Recording and Preserving the Natural World from the Fifteenth to the Twenty-First Century
Edited by Arthur MacGregor
With a Foreword by Sir David Attenborough
Contributors are: Marie Addyman, Peter Barnard, Paul D. Brinkman, Ian Convery, Peter Davis, Felix Driver, Florike Egmond, Annemarie Jordan Gschwend, Geoff Hancock, Stephen Harris, Hanna Hodacs, Stuart Houston, Dominik Huenniger, Rob Huxley, Charlie Jarvis, Malgosia Nowak-Kemp, Shepard Krech III, Mark Lawley, Arthur Lucas, Marco Masseti, Geoff Moore, Pat Morris, Charles Nelson, Robert Peck, Helen Scales, Han F. Vermeulen, and Glyn Williams.
Valentin Rineau, René Zaragüeta i Bagils and Michel Laurin
Edited by R. Sluys
Simulation-based and experimental studies are crucial to produce factual arguments to solve theoretical and methodological debates in phylogenetics. However, despite the large number of works that tested the relative efficiency of phylogenetic methods with various evolutionary models, the capacity of methods to manage various sources of error and homoplasy has almost never been studied. By applying ordered and unordered methods to datasets with iterative addition of errors in the ordering scheme, we show that unordered coding in parsimony is not a more cautious option. A second debate concerns how to handle reversals, especially when they are regarded as possible synapomorphies. By comparing analyses of reversible and irreversible characters, we show empirically that three-taxon analysis (3ta) manages reversals better than parsimony. For Brownian motion data, we highlight that 3ta is also more efficient than parsimony in managing random errors, which might result from taphonomic problems or any homoplasy generating events that do not follow the dichotomy reversal/ convergence, such as lateral gene transfer. We show parsimony to be more efficient with numerous character states (more than four), and 3ta to be more efficient with binary characters, both methods being equally efficient with four states per character. We finally compare methods using two empirical cases of known evolution.
Roman Croitor and Theodor Obada
Edited by A. van der Geer
This article reports antler remains from the Late Paleolithic site of Climăuți II (Republic of Moldova) confirming the presence of wapiti Cervus canadensis in the Late Pleistocene of Western Eurasia. The occurrence of wapiti in the East Carpathian area by 20 ky BP coincides with the local extinction of Megaloceros giganteus, Crocuta spelaea, and Ursus spelaeus, and substitution of local forest reindeer with grazing tundra-steppe Rangifer tarandus constantini. We here provide an overview of paleontological data and opinions on the presence of Cervus canadensis in Europe, a discussion on the taxonomic status and systematic position of the extinct deer Cervus elaphus palmidactyloceros, and propose a dispersal model for wapiti in Europe during the Late Pleistocene.
D. A. Caraballo and M. S. Rossi
Edited by V. Nijman
Subterranean rodents of the genus Ctenomys have experienced an explosive radiation and rapidly colonized the southern cone of South America. The torquatus group, one of the main groups of the genus, comprises several species and species complexes which inhabit the eastern part of the distribution of Ctenomys including southern Brazil, northern and central Uruguay and north-eastern Argentina. This group has undergone a high chromosomal diversification with diploid numbers varying from 41 to 70. The aim of this study was to investigate the origins of the torquatus group as well as its diversification patterns in relation to geography and cladogenesis. Based on mitochondrial cytochrome b nucleotide sequences we conducted a Bayesian multi-calibrated relaxed clock analysis to estimate the ages of the torquatus group and its main lineages. Using the estimated evolutionary rate we performed a continuous phylogeographic analysis, using a relaxed random walk model to reconstruct the geographic diffusion of the torquatus group in a temporal frame. The torquatus group originated during the early Pleistocene between 1.25 and 2.32 million years from the present in a region that includes the northwest of Uruguay and the southeast of the Brazilian state of Río Grande do Sul. Most lineages have dispersed early towards their present distribution areas going through subsequent range expansions in the last 800,000 – 700,000 years. Ctenomys torquatus went through a rapid range expansion for the last 200,000 years, becoming the most widespread species of the group. The colonization of the Corrientes and Entre Ríos Argentinean provinces supposes at least two crossing events across the Uruguay River between 1.0 and 0.5 million years before the present, in the context of a cold and dry paleoenvironment. The resulting temporal and geographic frame enables the comprehension of the incidence of both, the amplitude of distribution areas and divergence times into the patterns of chromosomal diversification found in the group.
In the course of the six centuries and more considered here, the concept of the naturalist and of the work that he or she undertakes in the field gradually took form and continues to develop. The status of the practitioners involved is so widely disparate as to defy easy categorization. In these introductory remarks some of the principal communities – arbitrarily defined – contributing to this movement are reviewed: a number of the most significant figures emerged from within the academic milieu, conducting their work initially in the tradition of the classical authors whose tracts held sway until the late Renaissance, yet they were increasingly reliant on the ocular evidence on which the New Science was built; others came from outside this tradition but contributed invaluable personal experience, insight and knowledge, practically acquired. Both are celebrated here, and their mutually enriching relationships are explored. Other essays here adopt a more specific focus in order to chart the ways in which the field practice that lies at the heart of this volume was guided and influenced by those who commissioned collecting expeditions – initially the founders of collectors’ cabinets, later the owners of systematic collections and ultimately the curators of veritable natural history museums. All of these operated in the role of sponsors for the field naturalists and all were anxious that material should reach them not only in optimum condition but with appropriate contextual data. Their demands were communicated variously in the course of correspondence, in printed pamphlets and ultimately in book-length instructions published for the benefit of those in the field: some of these texts are reproduced verbatim as appendices at the end of the volume.