DOI: 10.3897/vz.74.e127269

Authors: Dorottya Győrössy, Vuong Tan Tu, Gábor Csorba, Sanjan Thapa, Péter Estók, Gábor Földvári, Tamás Görföl

Abstract: Abstract In taxonomic works, the weight to be given to morphological, mitochondrial, or nuclear signals, and the assessment of differences as species or subspecies distinctions has also varied considerably over the past decades and is largely a subjective research decision. This apparent example of the “grey zone of taxonomy” underpins the need of critical studies of as many specimens as possible and of using both mitochondrial and nuclear genes in taxonomic-systematic studies, as phylogeny based on uniparentally inherited genes alone may not represent true evolutionary scenarios. Myotis sicarius, a species occurring thorough the Himalayan foothills was found for the first time out of South Asia, in North Vietnam. Analysis of topotypical and Vietnamese specimens revealed high mitochondrial heterogeneity – at the upper limit of the usual threshold of intraspecific difference – but only minute nuclear sequence and negligible morphological differences. Albeit the large geographic distance between the two records might suggest the existence of two putative reproductively isolated taxonomic units, based on the incongruent results we concluded that the split of geographic populations of M. sicarius into different taxa is unsupported. As a morphologically closely resembling species, we also reviewed the taxonomic status of the two morphological forms of M. annectans and synonymizing M. primula with M. annectans was also corroborated by our phylogenetic analyses.

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DOI: 10.3897/vz.74.e122418

Authors: Jason R. Ali, Uwe Fritz

Abstract: Abstract Our focus is the colonization history of the Galápagos’ vertebrate clades: 11 land-bound groups (eight reptiles, three rodents) and 13 taxa of flyers and swimmers (ten winged birds, two pinnipeds, one penguin). Using ‘colonization intervals’ and ‘colonization profiles’, it is clear that the two sets of taxa assembled very differently. The former includes older clades with between one, and potentially eight, predating the emergence of the oldest island (4 Mya). For the origin of some lineages, now-sunken landmasses associated with the Galápagos mantle-plume hotspot must have been involved, but for others it could reflect taxonomic uncertainties. In contrast, the taxa of flyers and swimmers are markedly younger, indicating either higher rates of colonization and extirpation for these sorts of animal, or continued genetic influx from mainland populations, or some combination of both factors. Concerning the first, possible drivers are the environmental stressors associated with the El Niño–La Niña climate system; the recent clades may be vulnerable to extreme events within the oscillation sequence, perhaps on ≥104-year timescales. Therefore, loose temporal thresholds might exist for the archipelago’s vertebrate groups beyond which selection fortifies them from the most challenging of seasonal states. Moreover, in a world of climate uncertainty, the findings appear relevant to conservation initiatives suggesting a focusing on the younger elements within the Galápagos’ biota.

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DOI: 10.3897/vz.73.e103319

Authors: Uwe Fritz, L. Lee Grismer, Marika Asztalos

Abstract: Using georeferenced photographic records of 2944 grass snakes from Germany, Austria, and northern Italy as well as previously published mtDNA sequences (n = 1062) and microsatellite data (n = 952) for grass snakes from the same regions, we examined whether or not coloration and pattern reliably allow to differentiate between Natrix natrix and N. helvetica and if so, whether the distribution patterns revealed by phenotypes and genetics are congruent. Furthermore, we used cline analyses across hybrid zones to test whether the phenotypic transition from one species to the other parallels the steep clines unveiled by genetics. Our results suggest that the two species can be reliably differentiated using coloration and pattern. The most powerful diagnostic traits are the presence/absence of side bars on the body flanks, the number of occipital spots, and the shape of the posterior dark occipital spot. The distributions of morphologically identified N. natrix and N. helvetica match their genetically confirmed ranges. Single conflicting individuals morphologically identified as N. natrix or hybrids within the distribution range of N. helvetica either represent misidentifications or translocated snakes. For the genetic markers and phenotypes, our cline analyses revealed concordant steep clines across hybrid zones. However, the southern part of the hybrid zone in Italy, for which no sufficient genetic data are available, should be studied in more detail because the phenotypic data suggest a smooth cline in this region. The unexpected high percentage of putative hybrids with dorsal stripes in this region also calls for further research. For northwestern Germany, another region for which no genetically verified records are available, iNaturalist data suggest that the contact zone of N. natrix and N. helvetica is near the Ems River and extends from there southeastwards to the region of Höxter, North Rhine-Westphalia.

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DOI: 10.3897/vz.72.e94711

Authors: Ingmar Werneburg, Irina Ruf

Abstract: Following the traditional and holistic concept of Vergleichende Entwicklungsgeschichte, Wolfgang Maier studied different aspects of vertebrate morphology, including dentition, the locomotor apparatus, nasal and ear regions. His work comprises investigations on pre- to postnatal stages of extant species as well as fossils and is mainly based on histological serial sections, but also on µCT data in recent years. This resulted in an integrative research agenda on the evolutionary biology of mammals and other vertebrates. Most of his studies are designed around the interrelationship of ontogenetic and functional adaptations and evolutionary transformations. The present collection in Vertebrate Zoology collates a series of research articles related to and in honor of Wolfgang Maier’s work. Invited colleagues of Maier provide current insights to their own research, in many cases inspired by his scholarship, ranging from mammalian to reptilian and fish comparative anatomy. In total, this volume contains 19 publications. They apply modern and traditional techniques to investigate the diversity of biological form. In so doing, they integrate traditional conceptual frameworks from the earliest days of morphological research more than two centuries ago.

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DOI: 10.3897/vz.72.e86968

Authors: Manfred Drack, Oliver Betz

Abstract: Here, we build on earlier work concerning notions of engineering design and investigate their conceptual connection to evolutionary biology. The basis for this work is an engineering design schema covering the central concepts of function, working principle and construction. Its relevance for evolutionary biology is explored by connecting these concepts to the so-called design space that is used in engineering optimisation. This tool makes it possible to distinguish various optima of performance and to visualise their robustness with respect to disturbances or changes in parameters. The robustness of morphological ‘constructions’ with regard to changes of shape is shown by means of examples from engineering and biology. The characteristics of various ‘landscapes’ in the design space is then related to the concept of evolvability, whereby we explore analogies between systems biology and morphology. A general property of phenotypes from the molecular to the organismal level seems to be that their ‘construction’ facilitates both their robustness and their exploration of the design space while maintaining the performance of the relevant functions at a high level.

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DOI: 10.3897/vz.72.e86348

Authors: Omar Rafael Regalado Fernández, Ingmar Werneburg

Abstract: A literature review showed that there is not a defined consensus on what specimens belong to Plateosaurus in current phylogenetic analyses, and after the assignation of SMNS 13200 as the neotype for Plateosaurus, the specimen composition of Plateosaurus as an operational taxonomic unit (OTU) needs to be addressed in further iterations of phylogenetic analyses. At least one of the specimens used to illustrate plateosaurian anatomy contains several characters identified in more derived sauropodomorphs commonly referred to as massopodans. This partial skeleton, traditionally known as specimen ‘GPIT IV’, was found in the lower dinosaur bone bed of the Obere Mühle, a Trossingen Formation outcrop, during an excavation in 1922 near the city of Tübingen, Germany. The holotype of Plateosaurus trossingensis and several other specimens referred to as this species were found in this level, which was initially interpreted as a synchronic deposit of animals. However, the current understanding of the Trossingen Formation indicates that this bed was probably a constant accumulation of carcasses through miring and transport down a river for hundreds of years. In this work, a framework to compare phylogenetic signals with morphological and histological data is provided to help in the species delineation of Plateosaurus, and support is found to refer the historic specimen ‘GPIT IV’ as a new genus and a new species.

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DOI: 10.3897/vz.72.e84983

Authors: Ingmar Werneburg, Uwe Hossfeld, Georgy S. Levit

Abstract: Here we report on a recently discovered student script of a lecture on paleontology given by Ernst Haeckel (1834–1919). The script dates to the summer semester of 1866, comprises 63 pages, and provides an overview of fossil invertebrate and mainly fossil vertebrate taxonomy and anatomy. It can be assumed that Russian student Nikolai Nikolajevitch Miklucho-Maclay (1846–1888), who later became a famous ethnologist, did not follow up on the lecture, but took the content directly from the lecture and from the blackboard in his notes. Hence, the drawings by Miklucho allow direct insight into Haeckel’s visualization of paleontology in the 1860s. We place the transcript in the historical context of understanding paleontology in the second half of the 19th century and address the break between zoology and embryology on the one hand and paleontology on the other, which is typical for Germany, partly persisting to this date. For that, we illustrate Haeckel’s integration of paleontology as part of a holistic triad, with fossil research gradually taking a back seat to zoology and embryology over the decades.

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DOI: 10.3897/vz.72.e79911

Authors: Shamna Rajan Palakkool, David J. Gower, Ramachandran Kotharambath

Abstract: Abstract The osteology of the poorly known grandisoniid caecilian Gegeneophis carnosus is described for the first time by applying high-resolution X-ray micro-computed tomography to some recently collected material. The ossified skeleton comprises a stegokrotaphic skull, lower jaw, and vertebral column. The braincase, composed of the sphenethmoid and os basale, is covered by eight other cranial elements viz. nasopremaxilla, frontal, parietal, squamosal, pterygoquadrate, maxillopalatine, vomer, and stapes. The eye is covered by the maxillopalatine, and an (open) orbit is absent. The sphenethmoid is not exposed and lacks a solum nasi or a ventral flange. The olfactory chamber lacks an olfactory eminence. Slight asymmetries were observed in the structure and/or size of the left and right frontals and parietals and in the number and size of some foramina. Except for pterygoquadrate and stapes, all bones are pierced by foramina for nerves and/or blood vessels. The lower jaw shows a typical caecilian pattern with dentigerous pseudodentary and edentulous pseudoangular. Numbers of vertebrae range from 123–130 (mean 126). The vertebrae are somewhat heterogenous, varying in size and proportions along the column. Comparisons are made with other caecilians, especially other grandisoniids. Aspects of the cranial osteology of Gegeneophis, such as the closed orbit, subterminal mouth, and stegokrotaphy are possible adaptations to dedicated fossoriality, but functional, behavioural, and field ecological data are not yet available to test this.

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DOI: 10.3897/vz.72.e87426

Authors: Uwe Fritz, Flora Ihlow

Abstract: Abstract We used a dataset of georeferenced photos of 5,751 grass snakes from iNaturalist to evaluate subspecific variation of Natrix natrix in coloration and pattern. Our results provide evidence that all four genetically delineated subspecies differ morphologically, although unstriped individuals of N. n. vulgaris are difficult to tell apart from the nominotypical subspecies. The iNaturalist dataset shows that the frequency of dark body coloration increases from south to north and from west to east. This trend is both concordant with taxonomic variation (the easternmost subspecies, N. n. scutata, being the darkest taxon) and variation within the same subspecies (in N. n. natrix and N. n. scutata more northern populations harbor more dark or melanistic individuals than more southern populations). Although available characters were limited to coloration and pattern traits, our study suggests that photo material from iNaturalist and similar platforms can be a valuable data source for studies on morphological variation. However, investigations using such databases can only supplement, but not replace, studies using museum material because only then measureable, meristic and genetic characters will be accessible.

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DOI: 10.3897/vz.72.e76256

Authors: Eduardo Ascarrunz, Marcelo R. Sánchez-Villagra

Abstract: The scutes of the carapace of extant turtles exhibit common elements in a narrow range of topographical arrangements. The typical arrangement has remained constant since its origin in the clade Mesochelydia (Early Jurassic), after a period of apparent greater diversity in the Triassic. This contribution is a review of the development and evolutionary history of the scute patterns of the carapace, seen through the lens of recent developmental models. This yields insights on pattern variations in the fossil record. We reinterpret the “supracaudal” scute and propose that Proganochelys had five vertebral scutes. We discuss the relationship between supramarginal scutes and Turing processes, and we show how a simple change during embryogenesis could account for origin of the configuration of the caudal region of the carapace in mesochelydians. We also discuss the nature of the decrease in number of scutes over the course of evolution, and whether macroevolutionary trends can be discerned. We argue that turtles with complete loss of scutes (e.g., softshells) follow clade-specific macroevolutionary regimes, which are distinct from the majority of other turtles. Finally, we draw a parallel between the variation of scute patterns on the carapace of turtles and the scale patterns in the pileus region (roof of the head) of squamates. The size and numbers of scales in the pileus region can evolve over a wide range, but we recognized tentative evidence of convergence towards a typical configuration when the scales become larger and fewer. Thus, typical patterns could be a more general property of similar systems of integumentary appendages.

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DOI: 10.3897/vz.72.e78092

Authors: L. Lee Grismer, Kin Onn Chan, Robert E. Lovich, Jesse L. Grismer

Abstract: This study re-analyzes morphometric and meristic data among island night lizards, Xantusia riversiana, from the California Channel Islands of San Clemente, Santa Barbara, and San Nicolas in order to ascertain whether the implementation of different statistical methods can recover different results that could potentially alter biological interpretations. Our results concur with a recent previous study demonstrating that the three island populations differ morphologically from one another and that the San Nicolas Island population is the most divergent. Several important aspects, however, of the previous study depart significantly from those recovered here. Our analyses found sexual dimorphism within each population for both morphometric and meristic characters to be relatively uncommon whereas the previous study found nearly all characters to be sexually dimorphic for all island populations. The previous study also recovered significant differences among the three island populations for all morphometric characters whereas far fewer differences were recovered in the present study. Both studies found few significant inter-island differences among the meristic characters. The discordances between these two studies stem from differences in the a priori treatment of the raw character data and the different downstream statistical analyses and visualization techniques used on those data. This was particularly relevant with the use here of an allometric growth algorithm for size-correcting the morphometric data not used in the previous study and by treating all three populations as independently evolving groups. We did not conduct analyses where data from the San Clemente and Santa Barbara island populations were conflated based on their subspecific designation (X. r. reticulata) and then compared to data from the independently evolving San Nicolas Island population. This imprudent use of taxonomy violates the assumptions of statistical independence. We emphasize that explicit justification for the use of particular statistical analyses should occur in all studies—especially if the results bear on the implementation of effective and efficient resource management programs.

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DOI: 10.3897/vz.71.e76453

Authors: Marika Asztalos, Dinçer Ayaz, Yusuf Bayrakcı, Murat Afsar, Cemal Varol Tok, Carolin Kindler, Daniel Jablonski, Uwe Fritz

Abstract: Using two mitochondrial DNA fragments and 13 microsatellite loci, we examined the phylogeographic structure and taxonomy of two codistributed snake species (Natrix natrix, N. tessellata) in their eastern distribution area, with a focus on Turkey. We found evidence for frequent interspecific hybridization, previously thought to be extremely rare, and for backcrosses. This underscores that closely related sympatric species should be studied together because otherwise the signal of hybridization will be missed. Furthermore, the phylogeographic patterns of the two species show many parallels, suggestive of a shared biogeographic history. In general, the phylogeographies follow the paradigm of southern richness to northern purity, but the dice snake has some additional lineages in the south and east in regions where grass snakes do not occur. For both species, the Balkan Peninsula and the Caucasus region served as glacial refugia, with several mitochondrial lineages occurring in close proximity. Our results show that the mitochondrial divergences in both species match nuclear genomic differentiation. Yet, in the former glacial refugia of grass snakes there are fewer nuclear clusters than mitochondrial lineages, suggesting that Holocene range expansions transformed the glacial hotspots in melting pots where only the mitochondrial lineages persisted, bearing witness of former diversity. On the other hand, the deep mitochondrial divergences in N. tessellata across its entire range indicate that more than one species could be involved, even though lacking microsatellite data outside of Turkey prevent firm conclusions. On the contrary, our microsatellite and mitochondrial data corroborate that N. megalocephala is invalid and not differentiated from sympatric populations of N. natrix. For Cypriot grass snakes, our analyses yielded conflicting results. A critical assessment of the available evidence suggests that N. natrix is a genetically impoverished recent invader on Cyprus and taxonomically not distinct from a subspecies also occurring in western Anatolia and the southern Balkans. Based on combined mitochondrial and nuclear genomic evidence we propose that for grass snakes the following subspecies should be recognized in our study region: (1) Natrix natrix vulgaris Laurenti, 1768, southeastern Central Europe and northern Balkans; (2) Natrix natrix moreotica (Bedriaga, 1882), southern Balkans, western Anatolia, and Cyprus; and (3) Natrix natrix scutata (Pallas, 1771), eastern Anatolia, Caucasus region, Iran, northeastern distribution range (from eastern Poland and Finland to Kazakhstan and the Lake Baikal region). Thus, Natrix natrix cypriaca (Hecht, 1930) becomes a junior synonym of N. n. moreotica and Natrix natrix persa (Pallas, 1814) becomes a junior synonym of N. n. scutata. Due to insufficient material, we could not resolve the status of Natrix natrix syriaca (Hecht, 1930) from the Gulf of İskenderun, southeastern Turkey.

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DOI: 10.3897/vz.71.e65934

Authors: Nanami Mano, Brody Wood, Lanre Oladipupo, Rebecca Reynolds, Jane Taylor, Emily Durham, James J. Cray, Chris Vinyard, Valerie B. DeLeon, Timothy D. Smith

Abstract: The sphenoid bone articulates with multiple basicranial, facial, and calvarial bones, and in humans its synchondroses are known to contribute to elongation of the skull base and possibly to cranial base angulation. Its early development (embryological, early fetal) has frequently been studied in a comparative context. However, the perinatal events in morphogenesis of the sphenoid have been explored in very few primates. Using a cross-sectional age sample of non-human primates (n=39; 22 platyrrhines; 17 strepsirrhines), we used microcomputed tomographic (µCT) and histological methods to track age changes in the sphenoid bone. In the midline, the sphenoid expands its dimensions at three growth centers, including the sphenooccipital, intrasphenoidal (ISS) and presphenoseptal (PSept) synchondroses. Bilaterally, the alisphenoid is enlarged via appositional bone growth that radiates outward from cartilaginous parts of the alisphenoid during midfetal stages. The alisphenoid remains connected to the basitrabecular process of the basisphenoid via the alibasisphenoidal synchondrosis (ABS). Reactivity to proliferating cell-nuclear antigen is observed in all synchondroses, indicating active growth perinatally. Between mid-fetal and birth ages in Saguinus geoffroyi, all synchondroses decrease in the breadth of proliferating columns of chondrocytes. In most primates, the ABS is greatly diminished by birth, and is likely the earliest to fuse, although at least some cartilage may remain by at least one-month of age. Unlike humans, no non-human primate in our sample exhibits perinatal fusion of ISS. A dichotomy among primates is the orientation of the ABS, which is more rostrally directed in platyrrhines. Based on fetal Saguinus geoffroyi specimens, the ABS was initially oriented within a horizontal plane, and redirects inferiorly during late fetal and perinatal stages. These changes occur in tandem with forward orientation of the orbits in platyrrhines, combined with downward growth of the midface. Thus, we postulate that active growth centers direct the orientation of the midface and orbit before birth.

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DOI: 10.3897/vz.71.e66756

Authors: Ingmar Werneburg, Serjoscha W. Evers, Gabriel Ferreira

Abstract: Abstract In recent years, paleoneurology became a very popular research field and hundreds of brain-endocasts were described. The interpretation of a dorsal protuberance of the brain-endocast puzzled researchers for a long time, the so-called (cartilaginous) rider. This is mainly because of technical limitations in the past and due to non-accessibility of comparative material. Using turtles as a case-study, we conducted a literature review and studied embryological data in addition to fossil and extant species’ endocasts. We assessed three hypotheses on the origin of the rider as relating to 1) the pineal gland, to 2) the blood vessel system, and to 3) skull roof elements. Based on our integrated anatomical observations, we refute the pineal gland hypothesis (1) and an exclusive blood vessel explanation (2). However, we show that, in most cases, the cartilaginous origin applies (3). The related cartilages, mainly the anterior process of the chondrocranial tectum synoticum, can persist until adulthood. Its diversity is interpreted in regard to the mechanical support for the temporal skull region, the shape of which has been shown to be in turn related to neck retraction and jaw mechanics. Finally, we highlight the value of embryological data to provide profound hypotheses for evolutionary research despite its low quantitative evaluability. We argue that it should be studied in conjunction with modern computer-aided data acquisition whenever possible.

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