TL;DR: Phylogeny of Recent Canidae (Mammalia, Carnivora) and relative reliability and utility of morphological and molecular datasets are compared.
Abstract: Zrzavý, J. & Řicankova, V. (2004). Phylogeny of Recent Canidae (Mammalia, Carnivora): relative reliability and utility of morphological and molecular datasets. — Zoologica Scripta, 33, 311–333.
Phylogenetic relationships within the Canidae are examined, based on three genes (cytb, COI, COII) and 188 morphological, developmental, behavioural and cytogenetic characters. Both separate and combined phylogenetic analyses were performed. To inspect the phylogenetic ‘behaviour’ of individual taxa, basic phylogenetic analysis was followed by experimental cladistic analyses based on different data-partition combinations and taxon-removal analyses. The following phylogeny of the Recent Canidae is preferred: (1) Urocyon is the most basal canid; (2) Vulpes is a monophyletic genus (including Fennecus and Alopex); (3) the doglike canids (DC) form a clade (=Dusicyon + Pseudalopex + Lycalopex + Cerdocyon + Atelocynus + Chrysocyon + Speothos + Lycaon + Cuon + Canis), split into two subclades, South American and Afro-Holarctic, with uncertain position of the Chrysocyon + Speothos subclade; (4) Canis is paraphyletic due to the position of Lycaon and Cuon. Otocyon and Nyctereutes are the most problematic canid genera, causing an unresolved branching pattern of Otocyon, Vulpes, Nyctereutes and DC clades. Reclassification of the two basal species of ‘Canis’ into separate genera is proposed (Schaeffia for ‘C.’ adustus, Lupulella for ‘C.’ mesomelas). Although the morphological dataset ranked poorly in both separate and simultaneous analyses (measured by number of minimum-length topologies, relative number of resolved nodes in the strict consensus of all minimum-length topologies, consistency and retention indices, nodal dataset influence, and number of extra steps required by the data partition to reach the topology of the combined tree), the morphological synapomorphies represent nearly one quarter of all synapomorphies in the combined tree. Among the hidden morphological support of the combined tree the developmental and behavioural characters are conspicuously abundant.
TL;DR: This paper investigated how a relatively social canid like the bush dog Speothos venaticus differs from the moderately social crab-eating fox Cerdocyon thous or the relatively solitary maned wolf Chrysocyon brachyurus.
TL;DR: Climatic adaptations as the main driving force of diversification for the South American canids is identified and both climate and competition impacts interspecific morphological variation.
Abstract: Species morphological changes can be mutually influenced by environmental or biotic factors, such as competition. South American canids represent a quite recent radiation of taxa that evolved forms very disparate in phenotype, ecology and behaviour. Today, in the central part of South America there is one dominant large species (the maned wolf, Chrysocyon brachyurus) that directly influence sympatric smaller taxa via interspecific killing. Further south, three species of similar sized foxes (Lycalopex spp.) share the same habitats. Such unique combination of taxa and geographic distribution makes South American dogs an ideal group to test for the simultaneous impact of climate and competition on phenotypic variation. Using geometric morphometrics, we quantified skull size and shape of 431 specimens belonging to the eight extant South American canid species: Atelocynus microtis, Cerdocyon thous, Ch. brachyurus, Lycalopex culpaeus, L. griseus, L. gymnocercus, L. vetulus and Speothos venaticus. South American canids are significantly different in both skull size and shape. The hypercarnivorous bush dog is mostly distinct in shape from all the other taxa while a degree of overlap in shape—but not size—occurs between species of the genus Lycalopex. Both climate and competition impacts interspecific morphological variation. We identified climatic adaptations as the main driving force of diversification for the South American canids. Competition has a lower degree of impact on their skull morphology although it might have played a role in the past, when canid community was richer in morphotypes.