Phylogeny and classification of the Sarcophagidae
The family Sarcophagidae is a member of the Tachinidae family-group (Oestroidea) and its monophyly is corroborated by several autapomorphic character states (Pape 1992). The following character states are here considered especially useful for diagnostic purposes:
The Sarcophagidae may be split in three subgroups, here considered as subfamilies.
Miltogramminae: Small to medium-sized species with large eyes, broad lower calypteres and an oval or slightly tapering abdomen. The peculiar Khowaba atrox from the Namib desert, however, is as big as many Sarcophaginae. Morphology of the terminalia is rather uniform, and only species of the genus Eumacronychia show a considerable structural diversity. Sexual dimorphism often present and then usually involving differences in colour pattern, males having a denser, brighter and more contrasting microtomentum, and the male fore tarsus may be equipped with specialised setae. Other examples are enlarged lower eye facets in the female, flattened female fore tarsus, flattened male arista, elongate male fore leg, and specialised setae on the tip of the male abdomen. The following characters may be autapomorphic for the subfamily, or at least for a clade containing the large majority of species:
Paramacronychiinae: Generally medium-sized species although they range from small specimens of Blaesoxiphella brevicornis no more than 3.5 mm long to the large Wohlfahrtia bella measuring up to 20 mm. Most species are densely covered with greyish or light brown microtomentum with a more or less distinct abdominal pattern of a median stripe and dark lateral spots. Extremes are the silvery microtomentose species of Wohlfahrtiodes with hardly any trace of abdominal spots, and the shining black and almost atomentose Nyctia halterata. The genus Brachicoma contains blackish species with more or less extensive bands of silvery microtomentum anteriorly on the abdominal tergites. The character states here considered autapomorphic for the subfamily all refer to the male terminalia and associated structures.
Sarcophaginae: Mostly large robust species, although species of Tricharaea (Sarcophagula) are among the smallest species of the family. The largest species are found in the Neotropical genus Peckia, with the bulky P. gulo probably taking the prize (specimens up to 23 mm seen by me). Very large species exceeding 20 mm also occur in Wohlfahrtia and in the group of extensively yellowish species of Sarcophaga (Sarcorohdendorfia). Colour patterns are fairly uniform, and a very widespread pattern is a grey thorax with three blackish vittae and a more or less tessellate or checkerboard-like pattern on the abdomen that changes with the incidence of light. Especially the Neotropical fauna, however, contains several exceptions, e.g., sparsely microtomentose metallic blue or blue-green species of Chlorosarcophaga (s.str.), the yellow Lepidodexia (Neophytodes) lindneri, species of Lepidodexia (Gymnocamptops) with a mat of red or yellow tomentum dorsally on the abdomen, and some almost completely black and atomentose species of Peckia (s.str.). The most conspicuously coloured Old World Sarcophaginae occur in the Indonesia-New Guinea-Bismarck archipelago where several species are partly or entirely yellowish. Species living on tropical sandy beaches are often extensively silvery like species of Tricharaea (Sarothromyia) in the New World, or even whitish like Sarcophaga (Leucomyia) alba in the Old World. The monophyly of the Sarcophaginae is remarkably well corroborated, and the following probably apomorphic groundplan features have only a very few exceptions:
The most probable sister group of the Sarcophagidae is the family Tachinidae. Pape (1992) corroborated this sister-group relationship by the shared possession of a single dorsal phallic sclerotization, i.e. fused dorsolateral processes, but higher level phylogeny within the Tachinidae family-group is still far from settled.
The Sarcophagidae are here divided into 3 subfamilies (see the paragraph on classification below), with a probable sister-group relationship between the Paramacronychiinae and the Sarcophaginae. This is corroborated by the shared possession of a ventrally displaced acrophallus, lack of epiphallus, and perhaps spherical female accessory glands (Pape 1992 and unpubl.).
Phylogenetic resolution beyond the first two splits is still poor, and only a few cladograms have been published. Roback (1954) presented a detailed evolutionary scenario of the Sarcophaginae, but although his work is a rich source of information, the phylogenetic hypotheses put forward are methodologically flawed when evaluated in a context of modern cladistic theory. Kurahashi & Kano (1984) analysed species-level phylogeny of Sarcophaga (Boettcherisca) using a statistical approach; Lopes (1984, 1990) provided hand-made cladograms of Lepidodexia (Notochaeta) and what he considered as a tribe Sarothromyiini (i.e., Tricharaea plus relatives showing male proclinate orbital bristles); Verves (1989) proposed a complete, hand-made genus-level phylogeny for the Miltogramminae (excluding Eumacronychia and Macronychia); and Pape (1994) analysed Blaesoxipha plus selected sarcophagine genera with phylogenetic inference programmes using parsimony.
Today we accomodate the species of Sarcophagidae in about one hundred valid genera, but it should be stressed that generic and subgeneric concepts are far from stable in the family. Considerable progress has been made in the Miltogramminae and Paramacronychiinae, where the monophyly of most genera is reasonably well corroborated. Note, however, that about half the genera in the Paramacronychiinae are monotypic and as such almost per definition monophyletic. The subfamily Sarcophaginae is especially difficult to split into well-defined monophyletic groups. Thus, many monotypic genera (or subgenera) may possibly be strongly apomorphic members of other (and thus paraphyletic) genera, and new species that consistently defer being fitted within any of the current genera are continuously being discovered. Methodological and conceptual differences among systematists combined with a remarkable uniformity in external morphology of the species have led to a multitude of generic classifications (compare the present ca 100 genera with Shewell's [1987:1162] statement that the Sarcophagidae contain "nearly 400 genera"). We are here following a taxonomic strategy of keeping the number of valid genera low within a concept of strict monophyly (Pape 1990, 1994). Monophyly as such may - and should - be tested in cladistic analyses, but many generic classifications may be proposed that are phylogenetically just as sound as the present. The 'quality' or 'success' of the overall approach thus ultimately depends on whether or not the generic concepts are taken up by the user community, which can only be evaluated retrospectively. It should also be stressed that the present generic classification differs from that presented in the regional catalogues largely due to a broader concept of many genera and as such is uncontroversial in a phylogenetic sense. Some of the larger genera have been divided into a number of possibly monophyletic subgenera on conceptual grounds and if 'distinct' groupings were apparent. This does not mean that we prefer formal subgeneric names for more informal species-group names, but it is considered appropriate considering the abundance of available genus-group names and the current lack of consensus on where to apply the generic rank. Most notable is perhaps the genus Sarcophaga sensu lato, which now contains about 800 valid species arranged in about 150 subgenera. The fact that more than half of these are monotypic may indicate that we should anticipate rather drastic changes in this classification. It may be noted that the present concept of subgenera in Sarcophaga (s.l.) largely corresponds to the genera of Sarcophagini applied by Verves (1986).
The classification with three subfamilies is considered as conceptually and mnemotechnically convenient as the three groups demarcate significant biological and morphological gaps, and alphabetical order equals phylogenetic sequence.
Content by T. Pape on behalf of the editorial group.
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Last updated: 25 October 2009.
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