The Mites of the Incas

Diagnostic views of Haplozetes similis, from Gil & Subías (1993) as 'Lauritzenia (Incabates) sinuatus'.

The oribatid mite genus Incabates was first established by Marie Hammer in 1961 for a species from Peru (not surprisingly, with that name). Since then, species have been assigned to Incabates from tropical and subtropical regions almost throughout the world (though not, as yet, from the Ethiopian bioregion—Subías 2004). Incabates belongs to the Haplozetidae, an oribatid family distinguished by their possession of well-developed pteromorphs that are often, though not always, mobile, and jointed chelate-dentate chelicerae (Norton & Behan-Pelletier 2009; the nature of oribatid 'pteromorphs' has been explained in an earlier post). Incabates has been distinguished from other haplozetid genera by having a series of dorsal glandular openings on the body developed as tubular saccules, ten pairs of setae on the notogaster (the dorsum of the main body), four pairs of setae around the genital opening, and three claws at the end of each leg (Gil & Subías 1993; Weigmann & Monson 2004). The presence of three claws rather than one claw on each leg appears to be correlated with an arboreal lifestyle in oribatids (Karasawa & Hijii 2008), and Incabates species do appear to be mostly associated with forest habitats.

There is a lot of taxonomic instability within (and indeed, around) the Haplozetidae, and it remains uncertain at this point whether Incabates should be recognised as a distinct taxon. Genera of Haplozetidae have often been distinguished by combinations of characters, often simply numerical (such as numbers of setae) and it may be debatable to what extent these characters reflect actual relationships. The checklist of the world oribatid fauna by Subías (2004) lists Incabates as a subgenus of Lauritzenia. Gil & Subías (1993) separated Lauritzenia (including Incabates) from the related genus Haplozetes by the number of genital setae (four pairs in Lauritzenia vs five in Haplozetes) and then divided each of these genera into subgenera on the basis of claw number (tridactyl Incabates vs monodactyl Lauritzenia subgenus Lauritzenia). However, Weigmann (2010) argued that these characters might be too plastic to warrant generic distinction, and supported treating all as a single undivided genus Haplozetes until the relationships within the group were better established. As yet, that's something we're still waiting on.

REFERENCES

Gil, J., & L. S. Subías. 1993. La familia Haplozetidae Grandjean, 1936 (Acari, Oribatida) en la Península Ibérica. Mediterránea Ser. Biol. 14: 23-30.

Karasawa, S., & N. Hijii. 2008. Vertical stratification of oribatid (Acari: Oribatida) communities in relation to their morphological and life-history traits and tree structures in a subtropical forest in Japan. Ecological Research 23 (1): 57-69.

Norton, R. A., & V. M. Behan-Pelletier. 2009. Suborder Oribatida. In: Krantz, G. W., & D. E. Walter (eds) A Manual of Acarology, 3rd ed., pp. 430-564. Texas Tech University Press.

Subías, L. S. 2004. Listado sistemático, sinonímico y biogeográfico de los ácaros oribátidos (Acariformes, Oribatida) del mundo (1758-2002). Graellsia 60 (número extraordinario): 3-305.

Weigmann, G. 2010. Oribatid mites (Acari: Oribatida) from the coastal region of Portugal. IV. The genera Coronoquadroppia, Scheloribates, Haplozetes and Pilobates. Soil Organisms 82 (3): 383-406.

Weigmann, G., & F. D. Monson. 2004. A new genus and species of Haplozetidae (Arachnida: Acari) from Great Britain with a key to the European genera. Journal of Natural History 38 (11): 1415-1420.

Obama's Lizard? Not So Fast

Left dentary of a currently unnamed lizard from the latest Cretaceous, from Longrich et al. (2012).

Yeah, this is a pretty petty point, but what would this site be if it didn't pertain to pedantry?

In the last week of last year, a paper was published in the Proceedings of the National Academy of Sciences of the USA on lizards in the latest Cretaceous and Palaeocene of North America (Longrich et al. 2012). The paper garnered itself a certain degree of media coverage because the authors chose to name a new genus after the current president of the United States, Barack Obama: see here and here, for instance. Because I was away for Christmas at the time, I've only just gotten the opportunity to look at the actual paper.

One thing immediately sprung out at me (and those of you familiar with my dribblings have probably already guessed what I'm about to say): this genus has not been validly published. The description is not in the body of the paper itself, it is in the online supplementary info. The printed section of the paper does include very brief diagnostic comments, but does not include an explicit designation of type material. Despite the recent decision by the ICZN allowing electronic-only publication, the supplementary info in Longrich et al. (2012) does not meet the requirements for valid electronic publication. It has not been registered with ZooBank, and it does not contain any indication of having been registered.'Obamadon gracilis' is hence an unavailable name, as are the other described taxa 'Pariguana lancensis' and 'Socognathus brachyodon'. Sorry. Once again, the space-saving requirements of a 'high-tier' science publication has shafted nomenclature.

I'd also be interested if anyone has comments on another potential problem. The supplementary info for Longrich et al. (2012) has been presented as a Microsoft Word document. I've no wish to argue the merits or otherwise of Microsoft Word per se—it's the word processing programme I generally use myself—but the ICZN requires that electronic publications be produced using a method that ensures 'widely accessible electronic copies with fixed content and layout'. PDF is not actually required, but is mentioned as an example of a format fulfilling this requirement. What about Word, though? Do you think a Word document can be regarded as 'fixed', or do you think that it is too easily altered after the fact?

REFERENCE

Longrich, N. R., B.-A. S. Bhullar & J. A. Gauthier. 2012. Mass extinction of lizards and snakes at the Cretaceous–Paleogene boundary. Proceedings of the National Academy of Sciences of the USA 109 (52): 21396-21401.

The Osangulariidae: Deep-Water Trochospires

Dorsal (spiral side), lateral and ventral (umbilical side) views of an Osangularia specimen, from here.

For today's post, I'm presenting for your consideration the Osangulariidae, a family within the rotaliid Foraminifera (see here for my post introducing the Rotaliida). These are benthic forams, mostly found in intermediate waters within the top few centimetres of sea floor sediment (Kaiho 1998). The Osangulariidae were first established as a distinct family of Foraminifera by Loeblich & Tappan (1964) to include trochospiral forams with bilamellar walls, with an important distinguishing feature separating osangulariids from related families being their granular rather than radial test wall structure. However, Loeblich & Tappan were criticised by Kaiho (1998) for their utilisation of this character. In developing a more lineage-based classification of the osangulariids and related taxa, Kaiho concluded that "radial-granular texture has no taxonomic significance in the suprageneric classification of calcareous trochospiral benthic foraminifera". Instead, Kaiho defined the Osangulariidae as trochospiral forams with an aperture on the umbilical side of the test, an angular periphery and strongly oblique sutures on the spiral side.

The Coniacian (Late Cretaceous) Globorotalites multisepta, from Loeblich & Tappan (1964).

The Osangulariidae first appeared in the Early Cretaceous, during the Aptian epoch. Kaiho (1998) recognised two subfamilies within the Osangulariidae, the Osangulariinae and the Globorotalitinae (not to be confused with the Globorotaliinae), regarding the slightly earlier-appearing Globorotalitinae as probably ancestral to the Osangulariinae. The Globorotalitinae possessed a test with a strongly inflated umbilical side, and can basically be described as looking like a jelly mould. Osangulariids of the globorotalitine type became extinct during the Palaeocene.

Nuttallides rugosus, from Todd 1965.

The Osangulariinae, on the other hand, have survived to the present day. Their most obvious distinction from the Globorotalitinae is the reduction of the umbilical side of the test, so that osangulariines tend to be more discus-shaped than jelly-mould-shaped. The earliest osangulariine genus, Protosangularia, appeared in the Aptian and survived until the Cenomanian in the early Late Cretaceous. At the end of the Cenomanian, a major anoxic event took place in the ocean followed by a reduction in world ocean temperatures. After this, Protosangularia was replaced by a number of other osangulariine genera appearing from the Turonian to the early Campanian (Kaiho 1998). Two of these genera, Osangularia and Nuttallides, are the family's modern representatives.

REFERENCES

Kaiho, K. 1998. Phylogeny of deep-sea calcareous trochospiral benthic Foraminifera: evolution and diversification. Micropaleontology 44 (3): 291-311.

Loeblich, A. R., Jr & H. Tappan. 1964. Treatise on Invertebrate Paleontology pt C. Protista 2. Sarcodina. Chiefly "thecamoebians" and Foraminiferida vol. 2. The Geological Society of America and The University of Kansas Press.

Lecantheae and/or Elatostemateae

Elatostema umbellatum var. majus, photographed by Michael Becker.

The Elatostemateae is a tribe of plants in the Urticaceae, the family that includes the nettles (Urticaceae in general have been looked at in an earlier post). Elatostemateae are mostly distinguished from other members of the Urticaceae by their generally tripartite perianth in the female flowers and their brush-like stigmas (Friis 1993). There seems to be some conflict over the appropriate name to call this group: Conn & Hadiah (2009) argued for the use of Elatostemateae, but many authors had previously called this group the Lecantheae. The argument hinges purely on a question of priority a bit too tedious to examine here.

Lecanthus peduncularis, photographed by Li-Chieh Pan.

The question may or may not be moot, anyway. Recent phylogenetic analyses of the Urticaceae have generally agreed that the Elatostemateae can be divided between two clades, one including the genus Elatostema and the other the genera Lecanthus and Pilea. The two groups are morphologically as well as molecularly distinguishable: species of Pilea and Lecanthus generally have opposite leaves, but in Elatostema one of each leaf pair has been greatly reduced (or lost) so that the leaves appear alternate. However, it is currently uncertain whether these two groups together form an exclusive clade. In the analyses by Hadiah et al. (2008), trnL-F sequence data was consistent with a monophyletic Elatostemateae, but rbcL data placed the Lecanthus-Pilea group closer to the tribe Urticeae than to Elatostema. This is not inherently unreasonable: as members of the Urticeae also have brush-like stigmas like those of Elatostemateae, the main distinction between the two tribes is the plesiomorphic absence in the latter of the stinging hairs that characterise the Urticeae.

Pilea fairchildiana, previously Sarcopilea domingensis, from Javier Francisco-Ortega.

Whether monophyletic or not, the Elatostemateae are mostly a tropical and subtropical group. They are mostly herbs and subshrubs, with a smaller number of shrub species. The centre of diversity is in the Old World; only the genus Pilea is found in the Americas. Members of the Elatostema group may be either all included in a single genus or divided between genera Elatostema, Procris and Pellionia distinguished by inflorescence characters. Pilea, the largest genus in the group, includes species in both the Old and New Worlds, of which some are commonly succulent. The Hispaniolan species Pilea fairchildiana has developed a rosulate growth form, remarkably similar to members of genera in the unrelated family Crassulaceae, such as Aeonium and Sempervivum. Until very recently, this species was considered distinctive enough to be placed in a separate genus Sarcopilea; Jestrow et al. (2012) demonstrated its more nested position. Economic usages of Lecantheae species are few: the leaves of some Pilea species, such as the artillery plants* P. microphylla and P. melastomoides, have some limited use as aromatic herbs, while some species of the Elatostema group are apparently used in Indonesia as shampoo.

*The name 'artillery plant' apparently refers to the way in while the male flowers fire forth their pollen, which is supposed to resemble gunsmoke.

REFERENCES

Conn, B. J., & J. T. Hadiah. 2008. Nomenclature of tribes within the Urticaceae. Kew Bulletin 64; 349-352.

Friis, I. 1993. Urticaceae. In: Kubitzki, K., J. G. Rohwer & V. Bittrich (eds) The Families and Genera of Vascular Plants vol. 2. Flowering Plants. Dicotyledons. Magnoliid, hamamelid and caryophylliid families pp. 612-629. Springer.

Hadiah, J. T., B. J. Conn & C. J. Quinn. 2008. Infra-familial phylogeny of Urticaceae, using chloroplast sequence data. Australian Systematic Botany 21: 375-385.

Jestrow, B., J. J. Valdés, F. Jiménez Rodríguez & J. Francisco-Ortega. 2012. Phylogenetic placement of the Dominican Republic endemic genus Sarcopilea (Urticaceae). Taxon 61 (3): 592-600.

Whistling for Whistlers

Male and juvenile golden whistler Pachycephala pectoralis, photographed by S. Lloyd. Female golden whistlers resemble the juveniles.

The name Pachycephalidae (or some orthographic variant thereof such as Pachycephalinae) has long been used to refer to a group of small insectivorous birds from the Australo-Papuan region (summarised by Boles 1979 as 'large-headed stout-bodied birds with poorly developed rictal bristles'). In the past, taxa included in the Pachycephalidae included the New Zealand genera Mohoua and Turnagra, the crested shriketit Falcunculus frontatus and the crested bellbird Oreoica gutturalis. However, as has often been the case with the more generalised groups of passerine birds, recent authors have tended to whittle the family's contents down as molecular studies have scattered the constituent taxa about the family tree. In its most recent iterations, Pachycephalidae generally corresponds to the taxa included in clade 'CC5CC6b' of Jetz et al. (2012), comprising primarily the genera Pachycephala and Colluricincla, plus a small number of satellite taxa.

Bare-throated whistler Pachycephala nudigula, photographed by Lars Peterssen.

The genus Pachycephala is currently used for the whistlers, a group of about forty species of mostly long-tailed, stout-billed birds, often (but not always) with sexually dimorphic coloration, with a contrasting pectoral band (most often black in the males) dividing the throat from the chest. The exact number of species in the genus is somewhat uncertain due to disagreements about the status of several constituent populations: the golden whistler P. pectoralis complex, for instance, includes over 65 named taxa variously recognised as species or subspecies (Jønsson et al. 2010). Species of Pachycephala are found from southeast Asia through to Fiji and Tonga. Some of you may recall whistlers featuring in Dougal Dixon's Life after Man as giving rise to an island radiation including nut-cracking, wood-pecking and predatory species (my only question being, who was the Hart that the plesiomorphic species in the radiation is supposed to be named after?)

Grey shrike-thrush Colluricincla harmonica, photographed by Sammy Sam.

Colluricincla, the shrike-thrushes, includes at least four species found in Australia and New Guinea (excluding a couple of species better included in Pachycephala). They are larger, slenderer and more narrow-headed than the whistlers, with less dimorphic coloration. The grey shrike-thrush C. harmonica of Australia has a high reputation as a singer. Some recent authors have also suggested inclusion of two further New Guinean species, the rusty pitohui Pitohui ferrugineus and white-bellied pitohui P. incertus, in Colluricincla. The genus Pitohui has been used to include a group of about half a dozen New Guinean species in the Pachycephalidae, which are relatively large and brash as pachycephalids go. They are variously reddish, black, or some combination of the two (the white-bellied pitohui has, as its name indicates, a yellowish-white underside). They have become most notorious in recent years for the discovery that, with the apparent exception of P. incertus, they are in fact toxic, with their skin and feathers containing batrachotoxins comparable to those found in the arrow-poison frogs of South America. Like the arrow-poison frogs, the birds probably do not generate the toxin themselves, but accumulate it from a diet of toxin-carrying melyrid beetles. However, molecular studies have indicated that the genus Pitohui as previously recognised is polyphyletic. The hooded pitohui P. dichrous and the variable pitohui P. kirhocephalus, the latter of which is the type species of the genus, are more closely related to the Oriolidae than the Pachycephalidae, while three species remain close to Pachycephala and Colluricincla. As well as the two species mentioned previously (which may be included in Colluricincla or maintained as a distinct genus for which the name Pseudorectes is available), the black pitohui 'Pitohui' nigrescens should be included in the Pachycephalidae as its own genus Melanorectes. As well as being closer to black than the reddish Pseudorectes species, Melanorectes nigrescens apparently possesses a 'peculiar musky smell' (Rothschild & Hartert 1913).

Rusty pitohui Pseudorectes ferrugineus, photographed by Dubi Shapiro.

The remaining two species of the Pachycephalidae are placed by Jønsson et al. (2010) in the genus Coracornis: the maroon-backed whistler C. raveni of Sulawesi and the Sangihe shrike-thrush C. sanghirensis of Sangihe, north of Sulawesi (as the vernacular name suggests, this species was previously included in Colluricincla). Neither of these species appears to be particularly well-known: in particular, C. sanghirensis was first described in 1881 but not observed again for over 100 years until 1985 (Rozendaal & Lambert 1999). So long was the gap between observations that several authors had, in this time, assumed that the original specimen must have been mislabelled and come from somewhere in New Guinea rather than Sangihe. This misinterpretation was encouraged by the belief that the species was directly related to the little shrike-thrush Colluricincla megarhyncha, found on the wrong side of the Wallace line to easily colonise Sangihe. As it is, C. sanghirensis is restricted to only a small area of forest on Sangihe at an altitude above 600 m, and was regarded by Rozendaal & Lambert (1999) as critically endangered. Its identification with Coracornis rather than Colluricincla was done by Jønsson et al. (2010) on the basis of molecular analysis; when comparing C. sanghirensis with Colluricincla, Rozendaal & Lambert (1999) do not appear to have also considered Coracornis raveni.

Sangihe shrike-thrush Coracornis sanghirensis, photographed by Marc Thibault.

REFERENCES

Boles, W, E. 1979. The relationships of the Australo-Papuan flycatchers. Emu 79: 107-110.

Jetz, W., G. H. Thomas, J. B. Joy, K. Hartmann & A. O. Mooers. 2012. The global diversity of birds in space and time. Nature 491: 444-448.

Jønsson, K. A., R. C. K. Bowie, R. G. Moyle, L. Christidis, J. A. Norman, B. W. Benz & J. Fjeldså. 2010. Historical biogeography of an Indo-Pacific passerine bird family (Pachycephalidae): different colonization patterns in the Indonesian and Melanesian archipelagos. Journal of Biogeography 37: 245-257.

Rothschild, W., & E. Hartert. 1913. List of the collections of birds made by Albert S. Meek in the lower ranges of the Snow Mountains, on the Eilanden River, and on Mount Goliath during the years 1910 and 1911. Novitates Zoologicae 20 (3): 473-527.

Rozendaal, F. G., & F. R. Lambert. 1999. The taxonomic and conservation status of Pinarolestes sanghirensis Oustalet 1881. Forktail 15: 1-13.