A new turtle from the La Colonia Formation (Campanian–Maastrichtian), Patagonia,Argentina, with remarks on the evolution of the vertebral column in turtles

Abstract: Patagoniaemys gasparinae gen. et sp. nov. is a new stem turtle found in central Patagonia, Chubut Province, Argentina, in outcrops of the La Colonia Formation (Campanian–Maastrichtian). This is a turtle of relatively large size (carapace length c. 70 cm), and the preserved remains of the holotype consist of skull fragments and several postcranial elements including a nearly complete vertebral column. A phylogenetic analysis shows Patagoniaemys gasparinae gen. et sp. nov. forming a monophyletic group with Otwayemys cunicularius and Mongolochelys efremovi, as a sister group to Meiolaniidae. A comprehensive review confirms that formed cervical vertebrae appeared independently several times during turtle evolution: in the clade that includes Patagoniaemys gasparinae gen. et sp. nov. and Meiolaniidae, in some baenids, in the total group Pleurodira and in crown group Cryptodira. Likewise, formed caudal vertebrae appeared several times in turtle evolution.     

Diversity,Relationships, and Biogeography of the Lambeosaurine Dinosaurs from the European Archipelago,with Description of the New Aralosaurin Canardia garonnensis

We provide a thorough re-evaluation of the taxonomic diversity, phylogenetic relationships, and historical biogeography of the lambeosaurine hadrosaurids from the European Archipelago. Previously published occurrences of European Lambeosaurinae are reviewed and new specimens collected from upper Maastrichtian strata of the south-central Pyrenees are described. No support is found for the recognition of European saurolophines in the available hadrosaurid materials recovered so far from this area. A new genus and species of basal lambeosaurine, Canardia garonnensis, is described on the basis of cranial and appendicular elements collected from upper Maastrichtian strata of southern France. C. garonnensis differs from all other hadrosaurids, except Aralosaurus tuberiferus, in having maxilla with prominent subrectangular rostrodorsal flange; it differs from A. tuberiferus in a few maxillary and prefrontal characters. Together with A. tuberiferus, C. garonnensis integrates the newly recognized tribe Aralosaurini. Inference of lambeosaurine interrelationships via maximum parsimony analysis indicates that the other three known European lambeosaurines are representatives of two additional subclades (tribes) of these hadrosaurids: Tsintaosaurini (Pararhabdodon isonensis) and Lambeosaurini (the Arenysaurus ardevoli-Blasisaurus canudoi clade). The tribes Aralosaurini, Tsintaosaurini, Lambeosaurini, and Parasaurolophini are formally defined and diagnosed for the first time. Three event-based quantitative methods of ancestral range reconstruction were implemented to infer the historical biogeography of European lambeosaurines: Dispersal-Vicariance Analysis, Bayesian Binary MCMC, and Dispersal-Extinction-Cladogenesis. The results of these analyses, coupled with the absence of pre-Maastrichtian lambeosaurines in the Mesozoic vertebrate fossil record of Europe, favor the hypothesis that aralosaurins and tsintaosaurins were Asian immigrants that reached the Ibero-Armorican island via dispersal events sometime during the Maastrichtian. Less conclusive is the biogeographical history of European lambeosaurins; several scenarios, occurring sometime during the Maastrichtian, are possible, from vicariance leading to the splitting of Asian or North American from European ranges to a dispersal event from North America to the European Archipelago.     

Upper Campanian–Maastrichtian chronostratigraphy of the Skælskør‐1 core,Denmark: correlation at the basinal and global scale and implications for changes in sea‐surface temperatures

The lithostratigraphy, calcareous nannofossil biostratigraphy, carbon‐ and oxygen‐isotope stratigraphy and gamma‐ray profile are presented for the Skælskør‐1 core, eastern Denmark. The correlation of carbon isotopes to Gubbio (Italy) and ODP Site 762C (Indian Ocean) provides the chronostratigrahical framework of the core through a tie to magnetostratigraphy. Two new carbon‐isotope excursions are defined for the uppermost Maastrichtian of the core and prove useful for long‐distance correlation. Twenty stratigraphic tie‐points are used for correlation of the upper Campanian–Maastrichtian interval by combining carbon‐isotope and gamma‐ray variations. Significant dissimilarities in the gamma‐ray profiles of the Danish Basin cores preclude the sole use of this tool for basin‐scale correlations. Bulk oxygen‐isotopes and semi‐quantitative abundance changes in the warm‐water calcareous nannofossil Watznaueria barnesiae and the cool‐water Kamptnerius magnificus highlight the following past changes in sea‐surface temperatures (SSTs): relatively warm late Campanian SSTs, cooling across the Campanian–Maastrichtian boundary and through the early Maastrichtian, warming across the early–late Maastrichtian transition, cooling in the late Maastrichtian, intense warming in the latest Maastrichtian chron C29r, followed by a very short episode of cooling immediately before the Cretaceous–Palaeogene boundary. The late Campanian–Maastrichtian evolution in sea water temperatures inferred from the Danish Basin is similar to that delineated at tropical latitude oceanic sites.     

A NEW SPINICAUDATAN GENUS (CRUSTACEA: ‘CONCHOSTRACA’) FROM THE LATE CRETACEOUS OF MADAGASCAR

Abstract: A new spinicaudatan genus and species, Ethmosestheria mahajangaensis gen. et sp. nov., is described from the Anembalemba Member (Upper Cretaceous, Maastrichtian) of the Maevarano Formation, Mahajanga Basin, Madagascar. This is the first spinicaudatan reported from the post‐Triassic Mesozoic of Madagascar. The new species is assigned to the family Antronestheriidae based on the cavernous or sievelike ornamentation on the carapace. Of well‐documented Mesozoic spinicaudatan genera, Ethmosestheria mahajangaensis is most closely related to Antronestheria Chen and Hudson from the Great Estuarine Group (Jurassic) of Scotland. However, relatively poor documentation of the ornamentation of most Gondwanan Mesozoic spinicaudatan species precludes detailed comparison among taxa. Ethmosestheria mahajangaensis exhibits ontogenetic trends in carapace growth: a change in carapace outline from subcircular/subelliptical to elliptical, and from very wide juvenile growth bands to narrow adult growth bands. Ornamentation style, however, does not vary with ontogeny. Ethmosestheria mahajangaensis individuals lived in temporary pools in a broad channel‐belt system within a semiarid environment; preserved desiccation structures on carapaces indicate seasonal drying out of pools within the river system. Specimens of Ethmosestheria mahajangaensis are preserved with exquisite detail in debris flow deposits; these are the first spinicaudatans reported from debris flow deposits. These deposits also contain a varied vertebrate fauna, including dinosaurs, crocodyliforms, turtles, and frogs. Rapid entombment of the spinicaudatan carapaces likely promoted early fossil diagenesis leading to highly detailed preservation.     

A strange new chelonioid turtle from the Latest Cretaceous Phosphates of Morocco

A new genus and species of huge marine turtle (superfamily Chelonioidea, epifamily Dermochelyoidae) is described from the Maastrichtian Phosphates of the Oulad Abdoun Basin of Morocco. A new type of feeding apparatus, adapted for a powerful crushing pattern, illustrates the noteworthy diversity of fossil vertebrates of the Maastrichtian-Ypresian Phosphates of Morocco. No other crushing cryptodire or bothremydid pleurodire has this morphology. During the Maastrichtian, the known crushing pattern of chelonioids was different, close to that of modern cheloniids, as illustrated in Morocco in the Maastrichtian Ganntour Basin and the Palaeogene Oulad Abdoun Basin. This new taxon exhibits unusual cranial characters (fusion of premaxillae associated with a backward and dorsal retraction of the naris, horizontal stretching of the dorsal meatus quadrati), that are shared only with another new turtle, known also from the same Maastrichtian Phosphates of Morocco.     

Systematics and evolutionary significance of the small Abrocomidae from the early Miocene of southern South America

Octodontoidea is the most species-rich clade among hystricomorph rodents, and has a fossil record going back to at least the late Oligocene. Affinities of fossils previous to the late Miocene differentiation of the extant families Abrocomidae, Echimyidae and Octodontidae are controversial, essentially because these fossils may share few apomorphies with modern species. In fact, pre-late Miocene representatives of Abrocomidae had not been recognised until very recently. Here we revise the early Miocene genus Acarechimys, originally assigned to Echimyidae, and alternatively to stem Octodontoidea or to Octodontidae. A systematic and parsimony-based phylogenetic analysis of the species traditionally included in Acarechimys showed that this genus is part of stem Abrocomidae. These results are primarily supported by morphology of the mandible and lower molars. Acarechimys is here restricted to three species, A. minutus, A. pulchellus and Acarechimys pascuali sp. nov., while another species, A. constans, is here transferred to a new abrocomid genus. The remaining species were nested within Octodontidae. According to these results, Abrocomidae might have been as diverse as its sister clade Octodontidae-Echimyidae during the late Oligocene–early Miocene. Extinction of this diversity would have resulted in marked loss of evolutionary history, with extant abrocomids being currently restricted to late-diverged euhypsodont representatives.     

Fossil wood of <Emphasis Type="Italic">Sequoioxylon burejense</Emphasis> sp. nov. (Taxodiaceae) from the Upper Cretaceous of the Zeya-Bureya Basin (Russian Far East)

A new species Sequoioxylon burejense Blokhina et M. Afonin (Taxodiaceae), identified on the basis of anatomical features of fossil wood from the Middle Maastrichtian (Upper Cretaceous) of the Zeya-Bureya Basin, Amur Region, Russian Far East, is described. The new species is characterized by mixed anatomical features of the modern representatives of the tribe Sequoieae. Cretaceous wood of Taxodiaceae was found in the Amur Region for the first time.     

Phylogeny and the fossil record of the Helophoridae reveal Jurassic origin of extant hydrophiloid lineages (Coleoptera: Polyphaga)

We performed a phylogenetic analysis focused on the hydrophiloid family Helophoridae (Coleoptera: Polyphaga) in order to test the phylogenetic position of selected Mesozoic fossils assigned to the Hydrophiloidea. The analysis is based on 92 characters of larvae and adults, and includes all extant subgenera of Helophorus and representatives of all other extant hydrophiloid families. Based on this analysis, we provide additional evidence for the monophyly of the helophorid lineage containing the families Helophoridae, Georissidae and Epimetopidae, as well as the first hypothesis on the phylogenetic relationships within Helophorus, revealing three main clades: Lihelophorus, Rhopalohelophorus and the clade of sculptured small subgenera; the subgenera Helophorus s.str., Gephelophorus, Trichohelophorus and Transithelophorus are recognized as paraphyletic or polyphyletic. Inclusion of fossil species in the analysis reveals the Mesozoic genera Hydrophilopsia Ponomarenko, Laetopsia Fiká?ek et al. (adult forms) and Cretotaenia Ponomarenko (larval form) as basal extinct clades of the helophorid lineage, the former genus Mesosperchus Ponomarenko as containing probable stem taxa of Helophorus and the former genus Mesohelophorus Ponomarenko as a member of the Helophorus clade containing extant sculptured subgenera. The extant subgenus Thaumhelophorus syn.nov. is synonymized with Rhopalohelophorus. Our results show that the family Helophoridae may be dated back to the late Jurassic (c. 150 Ma) and the extant clades of Helophorus back to the Early Cretaceous (c. 136 Ma). The basal groups of Helophorus and the supposed basal extinct lineages of the helophorid lineages are shown to be aquatic as adults. A single origin of trichobothria and ventral hydrophobic pubescence in the common ancestor of the Hydrophiloidea is hypothesized, indicating ancestral aquatic habits in the adult stage for the whole Hydrophiloidea.     

A new basal ornithopod dinosaur (Frenchman Formation,Saskatchewan, Canada), and implications for late Maastrichtian ornithischian diversity in North America

A small, articulated basal ornithopod skeleton from the Frenchman Formation (late Maastrichtian) of Saskatchewan (RSM P 1225.1), previously referred to the taxon Thescelosaurus, differs from both recognized species of this taxon (Thescelosaurus neglectus and Thescelosaurus garbanii). The differences are taxonomically informative and we recognize this specimen as the holotype of a new species, Thescelosaurus assiniboiensis sp. nov. , diagnosed by the presence of two autapomorphies, and displaying plesiomorphic traits more similar to those of Parksosaurus, than to those of the other Thescelosaurus species. The Frenchman Formation also harbours an intriguing faunal assemblage in which Thescelosaurus represents one of the most abundant dinosaur taxa, and preserves a relatively high proportion of small (putatively juvenile and subadult) specimens of many dinosaur taxa. Further work that increases the faunal sample from this formation, and that permits quantitative comparisons with contemporary formations, will determine whether or not these differences are well supported, and will determine their ultimate palaeobiological significance. Identification of a third species of Thescelosaurus from the late Maastrichtian of North America suggests that this taxon was more diverse than previously recognized, and shows an increase in diversity from the Campanian through the late Maastrichtian, contrasting the trends seen in most other ornithischian clades. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 163 , 1157–1198.     

Triassic turtle tracks and the origin of turtles

Turtle (Testudines) tracks, Chelonipus torquatus, reported from the early Middle Triassic (Anisian) of Germany, and Chelonipus isp. from the late Early Triassic (Spathian) of Wyoming and Utah, are the oldest fossil evidence of turtles, but have been omitted in recent discussions of turtle origins. These tracks provide significant clues as to how early the turtle Bauplan originated. Turtle trackways are quite distinctive: the manus and pes form tracks nearly parallel to the midline and indicate an unusually wide gait in which the trackway width is nearly equal to the stride length. These tracks do not fit what would be expected to be made by Triassic Pappochelys or Odontochelys, a supposed prototurtle and an early turtle, respectively. In contrast, these tracks are consistent with what would be expected from the Triassic turtles Proganochelys and Palaeochersis. The features inferred to be present in Triassic turtle tracks support the notion that Odontochelys is a derived aquatic branch of the turtle stem lineage rather than the ancestral state of all turtles. Chelonipus also resembles the Permian track Pachypes dolomiticus, generally assigned to a pareiasaur trackmaker. These revelations highlight the need to consider all available evidence regarding turtle origins, rather than just the body fossils.     

On the larval development of<Emphasis Type="Italic"> Eubranchipus grubii</Emphasis> (Crustacea,Branchiopoda, Anostraca), with notes on the basal phylogeny of the Branchiopoda

Selected larval stages of Eubranchipus grubii (Anostraca) from Danish temporary waters are examined by scanning electron microscopy in a phylogenetic context. The study focuses on limb development and body segmentation. It is shown that the large, proximal endite of the trunk limbs in the adult Anostraca is actually a fusion product of two smaller endites which make their appearance in the early larval development. This gives a total of six endites along the inner margin of the trunk limbs. An unsegmented endopod follows more distally. A small additional, seventh endite makes a short appearance in late larvae, but has disappeared in the adults. The naupliar feeding apparatus is of the same type as found in other branchiopods, and has previously been suggested as an autapomorphy for the Branchiopoda. The similarities between the naupliar feeding apparatus of E. grubii and other branchiopods include the presence of a long protopod with a characteristic morphology of the coxal and basipodal masticatory spines/setae, and a three-segmented mandibular palp (basipod and two endopod segments) with a largely similar setation in all taxa. The mode of trunk limb development is also the same as seen in most other recent branchiopods. The phylogenetic significance for the basal phylogeny of the Branchiopoda of these and other morphological features is discussed in relation to the phylogenetic position of two branchiopod fossils, Lepidocaris rhyniensis and Rehbachiella kinnekullensis. While R. kinnekullensis has previously been suggested to be a stem lineage branchiopod, the position of L. rhyniensis is more uncertain. Three different possible phylogenetic positions of L. rhyniensis are discussed: (a) L. rhyniensis as a stem lineage anostracan, (b) L. rhyniensis as a stem lineage branchiopod or (c) L. rhyniensis as a stem lineage phyllopod. It seems most plausible to consider L. rhyniensis a stem lineage anostracan.     

On Sea Turtle‐associated Craspedostauros (Bacillariophyta), with Description of Three Novel Species

The current study focuses on four species from the primarily marine diatom genus Craspedostauros that were observed growing attached to numerous sea turtles and sea turtle‐associated barnacles from Croatia and South Africa. Three of the examined taxa, C. danayanus sp. nov., C. legouvelloanus sp. nov., and C. macewanii sp. nov., are described based on morphological and, whenever possible, molecular characteristics. The new taxa exhibit characters not previously observed in other members of the genus, such as the presence of more than two rows of cribrate areolae on the girdle bands, shallow perforated septa, and a complete reduction of the stauros. The fourth species, C. alatus, itself recently described from museum sea turtle specimens, is reported for the first time from loggerhead sea turtles rescued in Europe. A 3‐gene phylogenetic analysis including DNA sequence data for three sea turtle‐associated Craspedostauros species and other marine and epizoic diatom taxa indicated that Craspedostauros is monophyletic and sister to Achnanthes. This study, being based on a large number of samples and animal specimens analyzed and using different preservation and processing methods, provides new insights into the ecology and biogeography of the genus and sheds light on the level of intimacy and permanency in the host–epibiont interaction within the epizoic Craspedostauros species.     

Small Theropod Teeth from the Late Cretaceous of the San Juan Basin,Northwestern New Mexico and Their Implications for Understanding Latest Cretaceous Dinosaur Evolution

Studying the evolution and biogeographic distribution of dinosaurs during the latest Cretaceous is critical for better understanding the end-Cretaceous extinction event that killed off all non-avian dinosaurs. Western North America contains among the best records of Late Cretaceous terrestrial vertebrates in the world, but is biased against small-bodied dinosaurs. Isolated teeth are the primary evidence for understanding the diversity and evolution of small-bodied theropod dinosaurs during the Late Cretaceous, but few such specimens have been well documented from outside of the northern Rockies, making it difficult to assess Late Cretaceous dinosaur diversity and biogeographic patterns. We describe small theropod teeth from the San Juan Basin of northwestern New Mexico. These specimens were collected from strata spanning Santonian – Maastrichtian. We grouped isolated theropod teeth into several morphotypes, which we assigned to higher-level theropod clades based on possession of phylogenetic synapomorphies. We then used principal components analysis and discriminant function analyses to gauge whether the San Juan Basin teeth overlap with, or are quantitatively distinct from, similar tooth morphotypes from other geographic areas. The San Juan Basin contains a diverse record of small theropods. Late Campanian assemblages differ from approximately co-eval assemblages of the northern Rockies in being less diverse with only rare representatives of troodontids and a Dromaeosaurus-like taxon. We also provide evidence that erect and recurved morphs of a Richardoestesia-like taxon represent a single heterodont species. A late Maastrichtian assemblage is dominated by a distinct troodontid. The differences between northern and southern faunas based on isolated theropod teeth provide evidence for provinciality in the late Campanian and the late Maastrichtian of North America. However, there is no indication that major components of small-bodied theropod diversity were lost during the Maastrichtian in New Mexico. The same pattern seen in northern faunas, which may provide evidence for an abrupt dinosaur extinction.     

New eutherian mammals from the Late Cretaceous of Aix‐en‐Provence Basin,south‐eastern France

In Europe, the fossil record of Late Cretaceous eutherian mammals is very poor, being limited to only three genera (Labes, Lainodon, and Valentinella). Labes and Lainodon are well‐supported members of Zhelestidae, a stem eutherian clade, whereas Valentinella is more problematic, being recently considered as a nomen dubium. Based on X‐ray computed microtomography scan analysis of the holotype and thanks to the discovery of new specimens from the type locality (Vitrolles‐La Plaine, south‐eastern France, late Maastrichtian), we reassessed Valentinella. This genus is unique by the association of an enlarged and rounded jaw angle with an assumed relatively elevated angular process, a bulbous protoconid and an unbasined heel on p4, a p5 with a wide molariform talonid and a hypoflexid, a robust molar morphology with a potential specialized crushing‐grinding function (bulbously constructed cusps, large talonid, and horizontal apical wear facet of the hypocone), a somewhat reduced m3 relative to m2, a premolariform ?P3 or ?P4 lacking a metacone, and a relatively large hypocone on upper molars. These characters reinstate Valentinella as a valid genus. We also describe Mistralestes arcensis gen. et sp. nov. from a newly discovered locality (La Cairanne‐Highway, south‐eastern France, late Campanian). Mistralestes is defined by a robust premolariform p5 with no cingulid, paraconid, or metaconid; molars with a transverse protocristid, a gradual compression of the trigonid from m1 to m3, and paracristid and protocristid probably confluent on m3. Based on comparisons and phylogenetic analyses, Valentinella and Mistralestes may belong to Zhelestidae but this systematic attribution remains poorly supported. © 2013 The Linnean Society of London     

A reassessment of Eocene parrotlike fossils indicates a previously undetected radiation of zygodactyl stem group representatives of passerines (Passeriformes)

In the past years, various Eocene fossil birds were described as stem group representatives of the zygodactyl Psittaciformes (parrots). These birds show quite disparate morphologies, which cast some doubt on the correct assignment of all of them to the psittaciform stem group. A reassessment of their affinities is further needed, because it was recently proposed that among extant birds, Psittaciformes and Passeriformes (passerines) form a clade and that passerines possibly derived from a zygodactyl ancestor. Here, phylogenetic analyses are performed, which for the first time also include representatives of the Zygodactylidae, the extinct zygodactyl sister taxon of the Passeriformes. The early Eocene Psittacopes was originally described as a stem group representative of Psittaciformes. However, none of the present analyses supported psittaciform affinities for Psittacopes and instead recovered this taxon in a clade together with zygodactylids and passerines. Also part of this clade are the early Eocene taxa Pumiliornis and Morsoravis, and it is detailed that Psittacopes and the long‐beaked and presumably nectarivorous Pumiliornis, with which it has not yet been compared, are very similar in their postcranial osteology. The present analysis corroborates the hypothesis of a zygodactyl stem species of passerines. To account for these results, Psittacopes is here assigned to a new higher‐level taxon and a new name is also introduced for the clade including Zygodactylidae and Passeriformes.     

A Giant Chelonioid Turtle from the Late Cretaceous of Morocco with a Suction Feeding Apparatus Unique among Tetrapods

Background

Secondary adaptation to aquatic life occurred independently in several amniote lineages, including reptiles during the Mesozoic and mammals during the Cenozoic. These evolutionary shifts to aquatic environments imply major morphological modifications, especially of the feeding apparatus. Mesozoic (250–65 Myr) marine reptiles, such as ichthyosaurs, plesiosaurs, mosasaurid squamates, crocodiles, and turtles, exhibit a wide range of adaptations to aquatic feeding and a broad overlap of their tooth morphospaces with those of Cenozoic marine mammals. However, despite these multiple feeding behavior convergences, suction feeding, though being a common feeding strategy in aquatic vertebrates and in marine mammals in particular, has been extremely rarely reported for Mesozoic marine reptiles.

Principal Findings

A relative of fossil protostegid and dermochelyoid sea turtles, Ocepechelon bouyai gen. et sp. nov. is a new giant chelonioid from the Late Maastrichtian (67 Myr) of Morocco exhibiting remarkable adaptations to marine life (among others, very dorsally and posteriorly located nostrils). The 70-cm-long skull of Ocepechelon not only makes it one of the largest marine turtles ever described, but also deviates significantly from typical turtle cranial morphology. It shares unique convergences with both syngnathid fishes (unique long tubular bony snout ending in a rounded and anteriorly directed mouth) and beaked whales (large size and elongated edentulous jaws). This striking anatomy suggests extreme adaptation for suction feeding unmatched among known turtles.

Conclusion/Significance

The feeding apparatus of Ocepechelon, a bony pipette-like snout, is unique among tetrapods. This new taxon exemplifies the successful systematic and ecological diversification of chelonioid turtles during the Late Cretaceous. This new evidence for a unique trophic specialization in turtles, along with the abundant marine vertebrate faunas associated to Ocepechelon in the Late Maastrichtian phosphatic beds of Morocco, further supports the hypothesis that marine life was, at least locally, very diversified just prior to the Cretaceous/Palaeogene (K/Pg) biotic crisis.     

Reappraisal of patterns of nonmarine cryptodiran turtle carotid circulation: evidence from osteological correlates and soft tissues

The turtle cranial circulation has been employed as an important source of phylogenetic information, but recent conflicting hypotheses of relationship within Testudinata suggest reevaluation of the utility of characters drawn from this complex. As a component of a comprehensive character analysis, the osteological correlates of the nonmarine cryptodiran turtle carotid circulation are herein subjected to high-resolution X-ray computed tomography, reassessed, and statistically investigated. Three different patterns of osteological correlates, indicating three disparate cranial circulatory patterns, are described, and this finding is corroborated by evidence from circulatory soft tissues. Members of the Trionychia and Kinosternoidea exhibit patterns that differ from the more widespread condition found in testudinoid taxa. This result differs from previous work, which has indicated the presence of only two major cranial circulatory patterns, and suggests that while cranial circulatory features may be phylogenetically informative, the information contained within them indicates patterns of relationship different from those previously hypothesized.