Divergent Morphology among Populations of the New Guinea Crocodile, Crocodylus novaeguineae (Schmidt, 1928): Diagnosis of An Independent Lineage and Description of A New Species.

Copeia. 107(3): 517-523.

Abstract:

The New Guinea Crocodile (Crocodylus novaeguineae) is a freshwater species of crocodilian endemic to the island of New Guinea in northern Oceania. The species inhabits both the country of Papua New Guinea in the east and Indonesian West Papua. Crocodylus novaeguineae occurs on both the northern and southern side of the Central Highlands, which span east to west dividing the entire island into northern and southern halves. Like most crocodilians, C. novaeguineae inhabits various grassy and forested swamps in lowland freshwater areas and has maintained both cultural and economic significance in the region for centuries. Neill (1971) and, more recently, Hall (1989) have suggested that Crocodylus novaeguineae on the northern side of the Central Highlands (“NCN”) and those on the southern side (“SCN”) are on independent evolutionary trajectories and should be taxonomically recognized. Hall (1989) attempted to affirm the suspicions of Neill and presented compelling morphological and ecological data to do so. Morphologically, the northern and southern hypothesized lineages differed in proportional premaxillary (PXS) to maxillary (MXS) length (NCN: MXS > PXS; SCN: PXS > MXS) and patterns of cervical squamation (NCN: >4 post-occipital scutes with lateral contiguity between them, anteromedial nuchal scute separation absent; SCN: 4 post-occipital scutes with lateral discontinuity between them, anteromedial nuchal scute separation present). Ecologically, C. novaeguineae south of the Central Highlands nest in the wet season, in synchrony with sympatric Crocodylus porosus, whereas north of the Central Highlands, nesting occurs in the dry season. Additionally, variation in reproductive strategy (clutch size and egg size ratios) was diagnosed between NCN and SCN; however, reproductive strategy is highly plastic, even intraspecifically, among crocodilians. Thus, these character states are not robustly interpretable as diagnostic. Phylogenetic approaches using molecular data were later tested and interpreted in the unpublished thesis of Gratten (2003) in which NCN and SCN were considered distinct operational taxonomic units in light of Hall (1989). A Bayesian analysis of relationships of Indo-Pacific Crocodylus using mtDNA curiously recovered a paraphyletic C. novaeguineae, rendered so by the purported Borneo Crocodile C. raninus, described from a skull and two preserved juveniles with no known extant population (Muller and Schlegel, 1844). NCN was recovered as more closely related to C. raninus than to SCN. This finding was attributed to either extremely recent divergence in NCN or misidentification of a dispersed or introduced NCN to Borneo from which the molecular sample was taken. Oaks (2011) recovered a paraphyletic C. novaeguineae; however, all samples of this species were from captive animals and identification of some samples appeared problematic. Thus, our analyses and comparisons herein only include populations of C. novaeguineae due to the lack of biologically reasonable comparisons. Crocodylus novaeguineae is the only freshwater crocodilian in the region besides the putative C. raninus. Little material with robust locality data exists in collections for this species, and in the absence of more specimens and diverse datasets we are unable to make additional comparisons. An improved analysis of morphological variation among populations of C. novaeguineae is warranted, given the ecological and molecular patterns that have slowly emerged. Here, we use multivariate geometric morphometric approaches to gain clarity on the differentiation of populations north and south of the Central Highlands by assessing cranial shape variation across the distribution. We aim to identify diagnostic characters for populations on independent evolutionary trajectories and test whether cranial shape variation corresponds to the hypothesized lineages (a clade north of the central highlands and one south). We predicted that specimens from drainages on the northern side would more closely resemble each other than specimens from drainages on the southern side of the highlands and that shape-based diagnostic characters would be revealed.

murray-biblio

Molecular phylogenetics and the diversification of hummingbirds.

Current Biology 24 (8): 910–916. doi:10.1016/j.cub.2014.03.016. PMID 24704078.

Summary:

The tempo of species diversification in large clades can reveal fundamental evolutionary mechanisms that operate on large temporal and spatial scales. Hummingbirds have radiated into a diverse assemblage of specialized nectarivores comprising 338 species, but their evolutionary history has not, until now, been comprehensively explored. We studied hummingbird diversification by estimating a time-calibrated phylogeny for 284 hummingbird species, demonstrating that hummingbirds invaded South America by ∼22 million years ago, and subsequently diversified into nine principal clades. Using ancestral state reconstruction and diversification analyses, we (1) estimate the age of the crown-group hummingbird assemblage, (2) investigate the timing and patterns of lineage accumulation for hummingbirds overall and regionally, and (3) evaluate the role of Andean uplift in hummingbird speciation. Detailed analyses reveal disparate clade-specific processes that allowed for ongoing species diversification. One factor was significant variation among clades in diversification rates. For example, the nine principal clades of hummingbirds exhibit ∼15-fold variation in net diversification rates, with evidence for accelerated speciation of a clade that includes the Bee, Emerald, and Mountain Gem groups of hummingbirds. A second factor was colonization of key geographic regions, which opened up new ecological niches. For example, some clades diversified in the context of the uplift of the Andes Mountains, whereas others were affected by the formation of the Panamanian land bridge. Finally, although species accumulation is slowing in all groups of hummingbirds, several major clades maintain rapid rates of diversification on par with classical examples of rapid adaptive radiation.

mcguire-biblio

PETZOLD, A., VARGAS-RAMIREZ, M., KEHLMAIER, C., VAMBERGER, M., BRANCH, DU PREEZ, L.,  HOFMEYR, M. D., MEYER,L., SCHLEICHER, A., ŠIROKÝ P. & FRITZ, U. (2014)

A revision of African helmeted terrapins (Testudines: Pelomedusidae: Pelomedusa), with descriptions of six new species.

Zootaxa 3795 (5): 523–548. doi: 10.11646/zootaxa.3795.5.2e

Abstract:

Using nearly range-wide sampling, we analyze up to 1848 bp of mitochondrial DNA of 183 helmeted terrapins and identify a minimum of 12 deeply divergent species-level clades. Uncorrected p distances of these clades equal or clearly exceed those between the currently recognized species of Pelusios, the genus most closely related to Pelomedusa. We correlate genetic discontinuities of Pelomedusa with data on morphology and endoparasites and describe six new Pelomedusa species. Moreover, we restrict the name Pelomedusa subrufa (Bonnaterre, 1789) to one genetic lineage and resurrect three further species from its synonymy, namely P. galeata (Schoepff, 1792), P. gehafie (Rüppell, 1835), and P. olivacea (Schweigger, 1812). In addition to these ten Pelomedusa species, we identify two further clades from Cameroon and Sudan with similar levels of genetic divergence that remain unnamed candidate species. We also note that some problematical terrapins from South Africa and Somalia may represent two additional candidate species. Some of the Pelomedusa species are morphologically distinctive, whilst others can only be identified by molecular markers and are therefore morphologically cryptic taxa.

petzold-biblio

Using historical genome‐wide DNA to unravel the confused taxonomy in a songbird lineage that is extinct in the wild.

Evol. Appl. 2021 Mar; 14(3): 698–709.

Published online 2020 Nov 7. doi: 10.1111/eva.13149

Abstract:

Urgent conservation action for terminally endangered species is sometimes hampered by taxonomic uncertainty, especially in illegally traded animals that are often cross‐bred in captivity. To overcome these problems, we used a genomic approach to analyze historical DNA from museum samples across the Asian Pied Starling (Gracupica contra) complex in tropical Asia, a popular victim of the ongoing songbird crisis whose distinct Javan population (“Javan Pied Starling”) is extinct in the wild and subject to admixture in captivity. Comparing genomic profiles across the entire distribution, we detected three deeply diverged lineages at the species level characterized by a lack of genomic intermediacy near areas of contact. Our study demonstrates that the use of historical DNA can be instrumental in delimiting species in situations of taxonomic uncertainty, especially when modern admixture may obfuscate species boundaries. Results of our research will enable conservationists to commence a dedicated ex situ breeding program for the Javan Pied Starling, and serve as a blueprint for similar conservation problems involving terminally endangered species subject to allelic infiltration from close congeners.

bavej-biblio

Is the northern chevrotain, Tragulus williamsoni Kloss, 1916, a synonym or one of the least-documented mammal species in Asia?

Raffles Bull. Zoology 65: 506–514.

Abstract:

The northern chevrotain, Tragulus williamsoni Kloss, 1916, was described, and for nearly a century remained known, from only one specimen. This had been collected from Meh Lem in northern Thailand in 1916. Following a taxonomic revision of the genus Tragulus, its taxonomic status was regarded as uncertain. New information from a Tragulus specimen from Xishuangbanna, Yunnan province, China, stored in the Kunming Institute of Zoology, corroborates the status of T. williamsoni as a distinct taxon based on skull measurements. The conservation implications of this finding include the urgent need to determine conclusively the taxonomic status of T. williamsoni, and its distribution and conservation status.

meijaard-biblio

Is the northern chevrotain, Tragulus williamsoni Kloss, 1916, a synonym or one of the least-documented mammal species in Asia?

Raffles Bulletin of Zoology 65: 506-514.

Abstract:

The northern chevrotain, Tragulus williamsoni Kloss, 1916, was described, and for nearly a century
remained known, from only one specimen. This had been collected from Meh Lem in northern Thailand in 1916.
Following a taxonomic revision of the genus Tragulus, its taxonomic status was regarded as uncertain. New
information from a Tragulus specimen from Xishuangbanna, Yunnan province, China, stored in the Kunming
Institute of Zoology, corroborates the status of T. williamsoni as a distinct taxon based on skull measurements. The
conservation implications of this finding include the urgent need to determine conclusively the taxonomic status
of T. williamsoni, and its distribution and conservation status.

meiijaard-biblio

The Identity of Mousedeer (Mammalia: Artiodactyla: Tragulidae) observed at Lower Peirce Fotest, Singapore.

NATURE IN SINGAPORE 2009 2: 467–473.

Volltext (PDF)

Conclusion:

The napu and the kanchil are usually distinguished from each other by the number of white stripes on their throat and
neck. However, in rare cases, this does not hold true at least for the kanchil. When coat colour and dark mid-ventral
stripe are taken into consideration, the mousedeer from Lower Peirce, thought to be a napu, Tragulus napu, should be a
kanchil, Tragulus kanchil fulviventer. Therefore, there is no recent record of wild napu on Singapore Island.

low-biblio

A review of the leucogaster species complex of the Indo-Pacific pomacentrid genus Amblyglyphidodon, with descriptions of two new species.

aqua, J. Ichthyol. Aquat. Biol. 5(4):139-152.

Zusammenfassung:

Bisher wurde angenommen, dass der indo-pazifische Pomacentride Amblyglyphidodon leucogaster aus verschiedenen, geografischen Farbvarianten bestesteht. Die vorliegende Untersuchung deutet jedoch auf einen aus vier Arten bestehenden Komplex hin: A. leucogaster (Bleeker) aus dem westlichen Pazifik und ostlichen Randgebiet des indischen Ozeans; A. orbicularis (Hombron u. Jacquinot) von Samoa, Fiji und Neu Kaledonien und zwei hier neu beschriebene Arten - A. indicus vom Roten Meer und Indischenr Ozean und A. melanopterus von Tonga. Die einzelnen Arten des leucogaster-Komplexes unterscheiden sich hautsachlich durch Kombinationen von Farbmustern und Anzahl der Kiemenreusen. Ein Bestimmungsschlussel fur Amblyglyphidodon-Arten liegt bei.

allen-biblio

Four new species of Cyprinodon from southern Nuevo León, Mexico, with a key to the C. eximius complex (Teleostei: Cyprinodontidae).

Ichthyological Explorations of Freshwaters, 4(4):295-308.

Abstract:

lozano-biblio

Four New Pupfishes of the Genus Cyprinodon from Mexico, with a Key to the C. eximius Complex.

Bull. Southern California Academy of Sciences 75(2): 68-75.

Volltext: http://www.nativefishlab.net/library/textpdf/15362.pdf

Abstract:

The pupfishes (genus Cyprinodon) referable to the C. eximius complex comprise seven species that are restricted to, or had their origin in, the Chihuahuan Desert region of Mexico and adjacent parts of Texas and New Mexico. Four are described as new; the remainder are C. eximius, C. atrorus, and C. latifasciatus. Most are of restricted distribution; one is extinct and another may be. Keys, diagnoses, and ranges are given for each species and all are illustrated. The distinctive morphometric characters of the new species are given. Life colors and color patterns are important in distinguishing species

miller-biblio