Cladistic Parsimony Research Articles

First Fossil Mallow Flower from Asia

Premise of research. Malvaceae, or the mallows, are well known from the Cenozoic sediments of Asia and are represented by many fossil leaves, woods, fruits, and pollen. Until now, no fossil flower of Malvaceae has been reported from the Cenozoic sediments of Asia. The present study addresses this lacuna and documents the evidence of mallow fossil flowers from Asia for the first time.Methodology. Fossil flowers similar to modern flowers of Bombax L. (Malvaceae) were recovered from the latest Neogene (Pliocene) sediments of Chotanagpur Plateau, Jharkhand, eastern India. They were revealed by careful removal of the overlying matrix and studied under light microscopy.Pivotal results. The fossil flowers, characterized by irregularly lobed sepals, obovate-elliptic petals, numerous stamens bearing long filaments, and characteristic reniform anthers, are recognized as a new species, Bombax asiatica Hazra, Bera et Khan sp. nov. A morphological principal coordinates analysis and cladistic parsimony analysis based on floral morphological characters support this taxonomic assignment.Conclusions. This fossil evidence provides an important clue about the past diversity and paleobiogeography of the mallow family in the Indian Cenozoic. This finding and earlier reported Malvaceae fossils from the same locality also indicate the presence of tropical climate in Jharkhand, eastern India, during the time of deposition.

Philosophy in Science: Some Personal Reflections

AbstractThe task of Philosophy in Science (PinS) is to use philosophical tools to help solve scientific problems. This article describes how I stumbled into this line of work and then addressed several topics in philosophy of biology—units of selection, cladistic parsimony, robustness and trade-offs in model building, adaptationism, and evidence for common ancestry—often in collaboration with scientists. I conclude by offering advice for would-be PinS practitioners.

Taphonomic attributes of the holotype of the lambeosaurine dinosaur Latirhinus uitstlani from the late Campanian of Mexico: Implications for its phylogenetic systematics

Latirhinus uistlani represents one of the most emblematic dinosaurs from Mexico. This hadrosaurid, originally described as a member of the Saurolophinae by Prieto-Márquez and Serrano-Brañas in 2012, was re-evaluated as a lambeosaurine by Ramírez-Velasco et al. (2021). In addition, these authors stated that the description of the 2012 holotype was based on a chimeric skeleton and designated a new holotype (a different concept for the composition of essentially the same individual). The composition of their 2021 holotype was based on the size, association and similar mode of preservation of the bones within the quarry. Notably, no details were provided regarding such mode of preservation. However, the fact that the type locality of L. uitstlani is an attritional bonebed where other similar-sized individuals were also present calls into question the criteria used by Ramírez-Velasco et al. (2021) in the composition of their holotype. We address this shortcoming by describing the taphonomic signature of the skeletal elements in the L. uitstlani holotype of Ramírez-Velasco et al. (2021), as well as that of other bones discussed collected from this species’ type locality and other sites of the late Campanian Cerro del Pueblo Formation. Our observations show different taphonomic attributes among the bones of the 2021 holotype, indicating that it is likely a chimera of different specimens. Such taphonomic attributes support a holotype for L. uitstlani consisting of the original elements listed in Prieto-Márquez and Serrano-Brañas (2012), with exclusion of the IGM 12712 jugal and a right scapula. We concur in that IGM 12712 is actually a fragmentary jugal, which represents an unusually large hadrosaurid specimen. We also tested the referral of L. uitstlani to Lambeosaurinae via a cladistic parsimony analysis that confirmed that this specimen belongs to that major clade of hadrosaurids; however, its relationships with other lambeosaurines remain unresolved. Finally, we re-evaluated the diagnostic utility of the characters used by Ramírez-Velasco et al. (2021) for referring other specimens to different hadrosaurid clades, concluding that several of them can only be referred to Hadrosauridae indeterminate.

Redefinition of the cicada tribe Hemidictyini Distant, 1905, status of the tribe Iruanini Boulard, 1993 rev. stat., and the establishment of Hovanini n. tribe and Sapantangini n. tribe (Hemiptera: Cicadidae).

A recent paper by Ruschel Campos (2019) on "leaf-winged" cicadas proposed a significant reorganization of the cicada tribe Hemidictyini Distant, 1905g, including synonymization of the monogeneric tribe Lacetasini Moulds Marshall, 2018 following the results of a cladistic parsimony analysis of morphological characters. In this study, we reconsider and revise the morphological analysis of Ruschel Campos and obtain new genetic data for Hemidictya. We find that their study suffers from a limited taxon sample, inappropriate outgroup selection, and misinterpretation of genitalic characters (uncus vs. claspers). We show that Hemidictyini sensu Ruschel Campos includes members of multiple tribes and subfamilies, and we conclude that some of the taxonomic transfers by Ruschel Campos are not supported. The two most similar and leaf-like cicadas, Hemidictya Burmeister, 1835 (South America) and Hovana Distant, 1905g (Madagascar), are probably not closely related but rather an excellent example of convergent evolution. Lacetasini is not a junior synonym of the Hemidictyini but a distinct part of the Tettigomyiinae Distant, 1905g as originally classified. We return or transfer the genera Lacetas Karsch, 1890, Iruana Distant, 1905g, Bafutalna Boulard, 1993, and Murphyalna Boulard, 2012 to the Lacetasini. With the transfer of all genera of Iruanina Boulard, 1993 and Bafutalnina Boulard, 1993 to Lacetasini and with Lacetas transferred to the Iruanina, Lacetasini n. syn. becomes a subjective junior synonym of Iruanini rev. stat. in the Tettigomyiinae. We assign Hovana to Hovanini n. tribe in the Tettigomyiinae and Sapantanga Distant, 1905g to Sapantangini n. tribe in the Tibicininae Distant, 1905b. We propose that Hemidictyini sensu novo contains only the genus Hemidictya and we assign the tribe to Tibicininae with a revised diagnosis.

No background in biology is assumed

No background in biology is assumed

Philosophical Primatology: Reflections on Theses of Anthropological Difference, the Logic of Anthropomorphism and Anthropodenial, and the Self-other Category Mistake Within the Scope of Cognitive Primate Research

This article investigates the deep-rooted logical structures underlying our thinking about other animals with a particular focus on topics relevant for cognitive primate research. We begin with a philosophical propaedeutic that makes perspicuous how we are to differentiate ontological from epistemological considerations regarding primates, while also accounting for the many perplexities that will undoubtedly be encountered upon applying this difference to concrete phenomena. Following this, we give an account of what is to be understood by the assertion of a thesis of anthropological difference, identifying, inter alia, a property that fulfils the exclusivity, universality, and constitution criteria and demarcates the differentia specifica between humans and other animals. Also, we systematically develop how such theses can be formulated more moderately. Furthermore, we account for different theoretical frameworks, argumentative schemes, and sociological factors whose employment is associated with theses as such. This endeavor is carried out under the guise of anthropomorphism and anthropodenial. Doing so, we show that both are favored by the logic of cognitive primate research. Put briefly, concepts like cladistic parsimony and arguments by analogy favor anthropomorphism whereas concepts like traditional parsimony and Morgan’s canon favor anthropodenial. We close by framing these topics in the light of the self-other category mistake that lies in ascribing exclusive self-properties to some other. Lastly, we probe this category mistake for potency and scope of implications and find it to be central to and unavoidably ingrained in our thinking about other animals.

Polyphyly of Mesadenus (Orchidaceae, Spiranthinae) and a New Genus from the Espinhaço Range, Southeastern Brazil

Abstract—Mesadenus displays an odd disjunction, with most species found in the southeastern USA, the Caribbean, and Mexico south to El Salvador, and two outliers occurring in southeastern Brazil. A recent molecular phylogenetic study showed that, as currently delimited, Mesadenus is polyphyletic, and further study of this little-known genus is required. Here we assessed relationships in Mesadenus and to other genera conducting a cladistic parsimony analysis of nucleotide sequences of nuclear (ITS) and plastid (matK-trnK, trnL-trnF) DNA for an enlarged sample of taxa, including five out of six currently accepted species of Mesadenus and representatives of nearly all (36 out of 41) genera of Spiranthinae, plus suitable outgroups. A detailed comparison of vegetative and floral attributes of relevant taxa was also conducted. Our results confirm the polyphyly of Mesadenus and support the creation of a new genus, Espinhassoa, to include Brazilian ‘Mesadenus’ glaziovii and ‘M.’ rhombiglossus (as Espinhassoa glaziovii and E. rhombiglossa, respectively). An identification key, descriptions, and illustrations of the two species herein included in Espinhassoa are provided.

Cladistic Parsimony, Historical Linguistics and Cultural Phylogenetics

AbstractHere, I consider the recent application of phylogenetic methods in historical linguistics. After a preliminary survey of one such method, i.e. cladistic parsimony, I respond to two common criticisms of cultural phylogenies: (1) that cultural artifacts cannot be modeled as tree‐like because of borrowing across lineages, and (2) that the mechanism of cultural change differs radically from that of biological evolution. I argue that while perhaps (1) remains true for certain cultural artifacts, the nature of language may be such as to side‐step this objection. Moreover, I explore the possibility that cladistic parsimony can be justified even if (2) is true by appealing to the inference pattern known among philosophers as ‘Inference to the Best Explanation’ (IBE).

Open versus closed recensions (Pasquali): Pros and cons of some methods for computer-assisted stemmatology

By comparing the results obtained through traditional qualitative stemmatics with those obtained through computer-assisted quantitative stemmatology, when both approaches are applied to two authentic data sets (the Old English Anglo-Saxon Chronicle and a Latin epitome of Marco Polo’s Devisement dou Monde ), this study aims at bringing to the fore the advantages and the disadvantages of some recent methods for the automatic grouping of witnesses, most of which are based on phylogenetic models. The analysis will show that not all the methods provide results which can be considered reliable in light of the evidence offered by a thorough scrutiny of the documentary history of the texts under inspection. In particular, the majority of computer-assisted methods succeed in providing very good information for detecting the grouping of witnesses, as well as for a preliminary evaluation of their variant readings. Yet, few offer some valuable guidance as to define the sub-groups. This limitation becomes crucial when the existence of more than one codex interpositus has to be postulated, i.e. when the historical evidence makes it clear that the actual textual transmission cannot conform to the mathematical ideal of cladistic parsimony. The latter case is particularly evident with ‘closed’ recensions, where mechanical reconstruction plays a heavier role, and the choice of variants follows rigorous stemmatic steps. On the other hand, the application of computer-assisted methods to ‘open’ recensions seems to give better results.

Phylogenetic relationships among sections Vicia, Sepium and Lathyroides of Vicia subgenus Vicia: isozyme evidence

Variation of 16 isozymes in Vicia barbazitae and in two couples of morphologically similar vetch species, Vicia grandiflora – Vicia qatmensis and Vicia lathyroides – Vicia cuspidata, in comparison with seven other species of sections Vicia and Sepium is described in order to get new evidence about their differentiation, phylogenetic and sectional position. The cladistic parsimony analysis of the isozyme data using Vicia bithynica of section Pseudolathyrus as an outgroup placed V. barbazitae, V. qatmensis, V. grandiflora and Vicia incisa in the same major clade together with Vicia sepium, the type species of section Sepium (syn. Atossa). The isozyme data thus support revised circumscription of sections Vicia and Sepium by transferring V. barbazitae, V. grandiflora, V. qatmensis and V. incisa, currently placed in section Vicia, to section Sepium. Vicia grandiflora and V. qatmensis differ in orthozymes of PGD-A, but are placed in the same subclade of sister species as both differ from the other species in shared orthozymes of FDH-A, PGM-A, DIA-B and AAT-C. Vicia cuspidata and V. lathyroides differ by unique orthozymes of MDH-B, PGM-A, SKD-A and SOD-B, but are placed in the same subclade of sister species as both differ from the other species in shared orthozymes of FDH-A, IDH-A, MDH-A and PGI-B.

Cladistics and mass extinctions: the example of conulariids (Scyphozoa, Cnidaria) and the End Ordovician Extinction Event

The End Ordovician Extinction Event (EOEE) had little impact on supra-specific diversity and disparity within the order Conulariida (Scyphozoa, Cnidaria). With two possible exceptions (Exoconularia and Glyptoconularia), all eight genera currently known from strata of middle or late Katian age survived the crisis, and nearly all of the discontinuous gross morphological features present in Ordovician and older genera are present in at least one of the surviving genera. A cladistic parsimony analysis of 17 genera, 12 of which occur in Ordovician strata, produced 3 major subclades and 7 less inclusive subclades within Conulariida. With one possible exception, the clade Anaconularia+Baccaconularia, all other monophyletic groups within Conulariida survived the EOEE. Moreover, additional, ghost lineages in the clade Climacoconus+Holoconularia+Notoconularia+Paraconularia+Reticulaconularia must have crossed the Ordovician–Silurian boundary. The minor impact of the EOEE on diversity and disparity within Conulariida probably reflects the eurytopic character and simple but efficient metabolism (possibly glycolysis-based) of this group.

Phylogeny of the sabertoothed felids (Carnivora: Felidae: Machairodontinae).

In recent years, advances in our understanding of feline relationships have cast light on their evolutionary history. In contrast, there have been no phylogenetic analyses on machairodont felids, making it difficult to develop an evolutionary hypothesis based on the recent surge of studies on their craniomandibular morphology and functional anatomy. In this paper, I provide the first phylogenetic hypothesis of machairodont relationships based on 50 craniomandibular and dental characters from a wide range of sabercats spanning more 11Myr. Exact searches produced 19 most-parsimonious trees, and a strict consensus was well resolved. The Machairodontinae comprise a number of basal taxa (Promegantereon, Machairodus, Nimravides, Dinofelis, Metailurus) and a well-supported clade of primarily Plio-Pleistocene taxa (Megantereon, Smilodon, Amphimachairodus, Homotherium, Xenosmilus) for which the name Eumachairodontia taxon novum is proposed. Previous phenetic grouping of machairodont taxa into three distinct groups, the Smilodontini, Homotherini and Metailurini, was not supported by cladistic parsimony analysis, and forcing monophyly of these groups was significantly incompatible with character distribution. Machairodonts as a clade are not characterized by saberteeth, i.e. hypertrophied, blade-like upper canines, but by small lower canines, as well as small M1 ; and large P3 parastyle. True saberteeth arose later and are a synapomorphy of the Eumachairodontia.

Phylogenetic and Biogeographic Analysis of Sphaerexochine Trilobites

BackgroundSphaerexochinae is a speciose and widely distributed group of cheirurid trilobites. Their temporal range extends from the earliest Ordovician through the Silurian, and they survived the end Ordovician mass extinction event (the second largest mass extinction in Earth history). Prior to this study, the individual evolutionary relationships within the group had yet to be determined utilizing rigorous phylogenetic methods. Understanding these evolutionary relationships is important for producing a stable classification of the group, and will be useful in elucidating the effects the end Ordovician mass extinction had on the evolutionary and biogeographic history of the group.Methodology/Principal FindingsCladistic parsimony analysis of cheirurid trilobites assigned to the subfamily Sphaerexochinae was conducted to evaluate phylogenetic patterns and produce a hypothesis of relationship for the group. This study utilized the program TNT, and the analysis included thirty-one taxa and thirty-nine characters. The results of this analysis were then used in a Lieberman-modified Brooks Parsimony Analysis to analyze biogeographic patterns during the Ordovician-Silurian.Conclusions/SignificanceThe genus Sphaerexochus was found to be monophyletic, consisting of two smaller clades (one composed entirely of Ordovician species and another composed of Silurian and Ordovician species). By contrast, the genus Kawina was found to be paraphyletic. It is a basal grade that also contains taxa formerly assigned to Cydonocephalus. Phylogenetic patterns suggest Sphaerexochinae is a relatively distinctive trilobite clade because it appears to have been largely unaffected by the end Ordovician mass extinction. Finally, the biogeographic analysis yields two major conclusions about Sphaerexochus biogeography: Bohemia and Avalonia were close enough during the Silurian to exchange taxa; and during the Ordovician there was dispersal between Eastern Laurentia and the Yangtze block (South China) and between Eastern Laurentia and Avalonia.

A New Species of Galeoglossum (Orchidaceae, Cranichidinae) from Oaxaca, Mexico

Abstract Galeoglossum cactorum, a new species of Orchidaceae from the Mixteca Alta region in the state of Oaxaca, Mexico, is described and illustrated. The new species is florally similar to G. thysanochilum but differs from it in the linear-oblanceolate leaves subtended by imbricating, dark brown cataphylls, presence of a papillose thickening near the base of the labellum, proportionately shorter, obtrapezoid column with lateral laminar wings and complete fusion of the filament, and prominent apicule of the rostellum remnant. A cladistic parsimony analysis of DNA sequences of nuclear ITS region and plastid matK-trnK region showed that the three currently recognized species of Galeoglossum form a monophyletic group, which is sister to Prescottia. Galeoglossum cactorum is known from a single locality in an unusual habitat for orchids, i.e. a xerophilous scrub dominated by columnar cacti of the genus Neobuxbaumia, whereas both G. thysanochilum and G. tubulosum dwell in oak- and pine-oak forest.

A new genus and species of rodent from the Brazilian Atlantic Forest (Rodentia: Cricetidae: Sigmodontinae: Oryzomyini), with comments on oryzomyine biogeography

We describe in this paper a new genus and species of cricetid rodent from the Atlantic Forest of Brazil, one of the most endangered eco-regions of the world. The new form displays some but not all synapomorphies of the tribe Oryzomyini, but a suite of unique characteristics is also observed. This new forest rat possesses anatomical characteristics of arboreal taxa, such as very developed plantar pads, but was collected almost exclusively in pitfall traps. Phylogenetic analyses of morphological (integument, soft tissue, cranial, and dental characters) and molecular [nuclear – Interphotoreceptor retinoid binding protein (Irbp) – and mitochondrial – cytochrome b– genes] datasets using maximum likelihood and cladistic parsimony approaches corroborate the inclusion of the new taxon within oryzomyines. The analyses also place the new form as sister species to Eremoryzomys polius, an Andean rat endemic to the Maranon valley. This biogeographical pattern is unusual amongst small terrestrial vertebrates, as a review of the literature points to few other similar examples of Andean–Atlantic Forest pairings, in hylid frogs, Pionus parrots, and other sigmodontine rodents. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 161, 357–390.

A methodological investigation of hominoid craniodental morphology and phylogenetics

The evolutionary relationships of extant great apes and humans have been largely resolved by molecular studies, yet morphology-based phylogenetic analyses continue to provide conflicting results. In order to further investigate this discrepancy we present bootstrap clade support of morphological data based on two quantitative datasets, one dataset consisting of linear measurements of the whole skull from 5 hominoid genera and the second dataset consisting of 3D landmark data from the temporal bone of 5 hominoid genera, including 11 sub-species. Using similar protocols for both datasets, we were able to 1) compare distance-based phylogenetic methods to cladistic parsimony of quantitative data converted into discrete character states, 2) vary outgroup choice to observe its effect on phylogenetic inference, and 3) analyse male and female data separately to observe the effect of sexual dimorphism on phylogenies. Phylogenetic analysis was sensitive to methodological decisions, particularly outgroup selection, where designation of Pongo as an outgroup and removal of Hylobates resulted in greater congruence with the proposed molecular phylogeny. The performance of distance-based methods also justifies their use in phylogenetic analysis of morphological data. It is clear from our analyses that hominoid phylogenetics ought not to be used as an example of conflict between the morphological and molecular, but as an example of how outgroup and methodological choices can affect the outcome of phylogenetic analysis.

Phylogenetic and biogeographic analysis of deiphonine trilobites

Cladistic parsimony analysis of the subfamily Deiphoninae Raymond, 1913 was conducted to produce a hypothesis of relationship for the group. The genera Deiphon Barrande, 1850 and Onycopyge Woodward, 1880 are found to be monophyletic, while the genus Sphaerocoryphe Angelin, 1854, as it was previously defined, is paraphyletic. A modified Brooks Parsimony Analysis using the phylogenetic hypothesis reveals patterns of biogeography, in particular, vicariance and geodispersal, during the Ordovician-Silurian. The analysis yields three major conclusions about deiphonine biogeography: Eastern Laurentia and Baltica were close enough during the late Ordovician to exchange taxa via sea level rise and fall; chance dispersal occurred between Northwestern Laurentia and Australia; and deiphonine trilobites likely originated in Baltica or Eastern Laurentia.

Heckethornia, a new genus of dimeropygid trilobites from the Lower Ordovician (Ibexian; Tulean and Blackhillsian) of the Great Basin, western USA

Heckethornia n. gen. is a morphologically striking clade of dimeropygid trilobites known from the Pogonip Group (Ordovician; Ibexian Series, Tulean and Blackhillsian stages) of western Utah and eastern Nevada. It includes seven species based on silicified material. All occur in the Fillmore Formation of western Utah, and four are also known from the Yellow Hill Limestone of eastern Nevada. Diagnostic features of Heckethornia include a highly vaulted exoskeleton with a tall pygidial “wall” made of fused outer pleurae, three pairs of large glabellar spines, two to three pairs of prominent pygidial spines, a single (or paired) large occipital spine(s), and an arc of tubercles on the librigenal field. Cladistic parsimony analysis suggests that the genus comprises two subclades, one including species with a single median occipital spine, and species with paired occipital spines or tubercles in the other. New species are H. smithi , H. hyndeae , H. numani , H. bowiei , H. morrisseyi , and H. ballionae .

Phylogenetic relationships of Cranichidinae and Prescottiinae (Orchidaceae, Cranichideae) inferred from plastid and nuclear DNA sequences

Phylogenetic relationships of subtribes Cranichidinae and Prescottiinae, two diverse groups of neotropical terrestrial orchids, are not satisfactorily understood. A previous molecular phylogenetic study supported monophyly for Cranichidinae, but Prescottiinae consisted of two clades not sister to one another. However, that analysis included only 11 species and eight genera of these subtribes. Here, plastid and nuclear DNA sequences are analysed for an enlarged sample of genera and species of Cranichidinae and Prescottiinae with the aim of clarifying their relationships, evaluating the phylogenetic position of the monospecific genera Exalaria, Ocampoa and Pseudocranichis and examining the value of various structural traits as taxonomic markers. Approx. 6000 bp of nucleotide sequences from nuclear ribosomal (ITS) and plastid DNA (rbcL, matK-trnK and trnL-trnF) were analysed with cladistic parsimony and Bayesian inference for 45 species/14 genera of Cranichidinae and Prescottiinae (plus suitable outgroups). The utility of flower orientation, thickenings of velamen cell walls, hamular viscidium and pseudolabellum to mark clades recovered by the molecular analysis was assessed by tracing these characters on the molecular trees. Spiranthinae, Cranichidinae, paraphyletic Prescottia (with Pseudocranichis embedded), and a group of mainly Andean 'prescottioid' genera (the 'Stenoptera clade') were strongly supported. Relationships among these clades were unresolved by parsimony but the Bayesian tree provided moderately strong support for the resolution (Spiranthinae-(Stenoptera clade-(Prescottia/Pseudocranichis-Cranichidinae))). Three of the four structural characters mark clades on the molecular trees, but the possession of a pseudolabellum is variable in the polyphyletic Ponthieva. No evidence was found for monophyly of Prescottiinae and the reinstatement of Cranichidinae s.l. (including the genera of 'Prescottiinae') is favoured. Cranichidinae s.l. are diagnosed by non-resupinate flowers. Lack of support from parsimony for relationships among the major clades of core spiranthids is suggestive of a rapid morphological radiation or a slow rate of molecular evolution.

A molecular phylogenetic analysis of Diuris (Orchidaceae) based on AFLP and ITS reveals three major clades and a basal species

Diuris is a terrestrial orchid genus of at least 61 and possibly more than 100 species, restricted to Australia except for one species endemic in Timor. Distinctive species groups have respective eastern and western centres of distribution. Although species affinities have been vaguely understood for many years, no formal infrageneric treatment has been undertaken as Diuris possesses few reliable morphological characters for a classification system. We have undertaken cladistic parsimony and Bayesian phylogenetic analyses of Diuris by using the ITS1–5.8S–ITS2 region of nuclear rDNA and morphological characters, with a subset of samples also studied by amplified fragment length polymorphism (AFLP) as an independent test of phylogenetic relationships. Four major clades with strong bootstrap support were resolved and are named here according to a recently published classification; D. sulphurea forms a lineage (subg. Paradiuris) of its own that is well supported as the sister to the rest of Diuris. Two other major eastern clades contained species related to D. maculata (subg. Xanthodiuris) and D. punctata (subg. Diuris), respectively. Although these latter two subgenera are genetically well resolved, there is minimal genetic variation at species level, consistent with recent, rapid speciation. A fourth clade (subg. Hesperodiuris) has a centre of distribution in Western Australia, and has more genetic and morphological variation than the eastern subgenera. Total evidence analysis provides support for the western clade being sister group to the two eastern subgenera Diuris and Xanthodiuris; however, this relationship was not resolved by molecular data. Hybridisation is known to be common among species within subgenera Diuris and Xanthodiuris. Instances of incongruence between different datasets were found suggestive of hybridisation events between species of different sections of Diuris.