A Juvenile Specimen of Archaeorhynchus Sheds New Light on the Ontogeny of Basal Euornithines

The ontogenetic development of extant birds is characterized by rapid growth, bone fusion and an early onset of flight ability. In contrast, little is known about how these ontogenetic traits evolved in the bird stem lineage, and the available data pertains primarily to Enantiornithes. Here, we describe an almost complete skeleton of a juvenile euornithine bird (LNTU-WLMP-18) from the Early Cretaceous Jiufotang Formation (Aptian), which was discovered near Lamadong Town (Jianchang County, Liaoning, China). Despite its completeness, bone preservation is rather poor. Thus, to increase the contrast between bone tissue and matrix, we used cyan-red-based autofluorescence photography. The specimen is more or less articulated and exposed in ventral aspect. The jaws are edentulous, the coracoid bears a procoracoid process, and the ischium lacks a proximodorsal process. The pedal unguals are short and barely curved, indicating a ground-dwelling lifestyle. Feathers, including long primaries, are present as carbonized traces. Several characters indicate that LNTU-WLMP-18 is a juvenile: the bone surface has a coarsely striated texture and no fusion is evident between the carpals and metacarpals, between the tibia and the astragalus and calcaneum, or among the metatarsals. Although juvenile characters have the potential to impede accurate identification of the specimen, morphological comparisons and cladistic analysis identify LNTU-WLMP-18 as most likely referable to the basal euornithine Archaeorhynchus, which would make the specimen the first juvenile bird from the Jehol Group that could be assigned to a specific taxon. Based on its size and the incomplete ossification of the bone surface, LNTU-WLMP-18 represents the smallest and therefore youngest known individual of this genus. A statistical comparison of limb proportions shows that the forelimbs of LNTU-WLMP-18 are significantly shorter than the hindlimbs, while the forelimbs are longer than the hindlimbs in subadult and adult individuals. This is different from the situation in some Enantiornithes, in which the forelimbs exceed the length of the hindlimbs even in hatchlings. Similar to Enantiornithes, Archaeorhynchus probably exhibit an early onset of flight ability, as indicated by the extensive wing plumage in LNTU-WLMP-18. Finally, the lack of gastroliths in the visceral cavity might indicate a dietary shift in Archaeorhynchus during ontogeny. As a small-bodied, ground-dwelling, seed-eating bird with a precocial ontogeny, Archaeorhynchus filled an ecological niche that later allowed early crown birds to survive the K-Pg mass extinction.

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Cambrian bivalved arthropod reveals origin of arthrodization

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2012.1958 ◽

2012 ◽

Vol 279 (1748) ◽

pp. 4699-4704 ◽

Cited By ~ 65

Author(s):

David A. Legg ◽

Mark D. Sutton ◽

Gregory D. Edgecombe ◽

Jean-Bernard Caron

Keyword(s):

Cladistic Analysis ◽

Major Constituent ◽

Burgess Shale ◽

Sea Spiders ◽

Horseshoe Crabs ◽

Stem Lineage ◽

Trunk Limbs ◽

Shale Formation ◽

Early Palaeozoic

Extant arthropods are diverse and ubiquitous, forming a major constituent of most modern ecosystems. Evidence from early Palaeozoic Konservat Lagerstätten indicates that this has been the case since the Cambrian. Despite this, the details of arthropod origins remain obscure, although most hypotheses regard the first arthropods as benthic predators or scavengers such as the fuxianhuiids or megacheirans (‘great-appendage’ arthropods). Here, we describe a new arthropod from the Tulip Beds locality of the Burgess Shale Formation (Cambrian, series 3, stage 5) that possesses a weakly sclerotized thorax with filamentous appendages, encased in a bivalved carapace, and a strongly sclerotized, elongate abdomen and telson. A cladistic analysis resolved this taxon as the basal-most member of a paraphyletic grade of nekto-benthic forms with bivalved carapaces. This grade occurs at the base of Arthropoda (panarthropods with arthropodized trunk limbs) and suggests that arthrodization (sclerotization and jointing of the exoskeleton) evolved to facilitate swimming . Predatory and fully benthic habits evolved later in the euarthropod stem-lineage and are plesiomorphically retained in pycnogonids (sea spiders) and euchelicerates (horseshoe crabs and arachnids).

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A new species of the genus Anahita Karsch, 1879 (Araneae: Ctenidae) from Hainan Island, China

Zootaxa ◽

10.11646/zootaxa.2839.1.4 ◽

2011 ◽

Vol 2839 (1) ◽

pp. 85

Author(s):

FENG ZHANG ◽

DONG-SHENG HU ◽

GUANG-XIN HAN

Keyword(s):

New Species ◽

Cladistic Analysis ◽

Hainan Island ◽

Asian Species ◽

The Family ◽

Juvenile Specimen ◽

A New Species

The spider genus Anahita Karsch, 1879 includes 21 species (Platnick 2011). There has been no revision of the genus and a recent cladistic analysis of the family Ctenidae (Silva 2003) suggested that Anahita was not monophyletic. However, Silva (2003) transferred Anahita isaloensis Ono, 1993 to Vulsor Simon, 1888 and now all species in the genus can be recognised by the absence of the retrolateral tibial apophysis and the presence of a hyaline area in the female epigynum. Fourteen species of Anahita are distributed in Africa, two species are reported from America and five species are known from Asia; A. fauna Karsch, 1879, A. maolan Zhu, Chen & Song, 1999, A. punctata (Thorell, 1890), A. samplexa Yin, Tang & Gong, 2000 and A. syriaca (O. Pickard-Cambridge, 1872). Four of the five Asian species have been described or redescribed recently (Song et al. 1999; Zhu et al. 1999; Yin et al. 2000; Levy 2003) and A. punctata is known only from a juvenile specimen collected in Sumatra, Indonesia (Thorell 1890).

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The anatomy and relationships of Haasiophis terrasanctus, a fossil snake by well-developed hind limbs from the Mid-Cretaceous of the Middle East

Journal of Paleontology ◽

10.1017/s0022336000044231 ◽

2003 ◽

Vol 77 (3) ◽

pp. 536-558

Author(s):

Olivier Rieppel ◽

Hussam Zaher ◽

Eitan Tchernov ◽

Michael J. Polcyn

Keyword(s):

Middle East ◽

Hind Limb ◽

Upper Cretaceous ◽

Cladistic Analysis ◽

Original Description ◽

Current Debate ◽

Hind Limbs ◽

Juvenile Specimen ◽

Methodological Problems ◽

Early Upper

The fossil snake species Haasiophis terrasanctus Tchernov, Rieppel, Zaher, Polcyn, and Jacobs, 2000, from the early Upper Cretaceous of the Middle East, is described and illustrated, following a review of the current debate on snake relationships and origins. The description and discussion presented here adds important detail to the knowledge of this taxon and its phylogenetic significance beyond the limited account presented in the original description of Haasiophis. The species is remarkable in that it shows the skull of a relatively advanced (i.e., macrostomatan) snake, yet preserves well-developed hind limbs. The hind limb includes a femur, tibia, fibula, astragalus, calcaneum, distal tarsal four, and remains of four metatarsals and two phalanges. Haasiophis cannot be considered a juvenile specimen of Pachyrhachis. The implications of the presence of well-developed hind limbs in Haasiophis, Pachyrhachis, and Podophis for the cladistic analysis of the phylogenetic interrelationships of these fossil snakes is discussed. The presence of well-developed hind limbs in Pachyrhachis and Haasiophis also creates methodological problems for the cladistic analysis of the phylogenetic relationships of these fossil snakes. Scenarios of snake origins are reviewed and found to be deficient in the absence of a well-corroborated hypothesis of snake relationships within Squamata.

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The phylogeny of the stomatopod Crustacea

Australian Journal of Zoology ◽

10.1071/zo00042 ◽

2000 ◽

Vol 48 (6) ◽

pp. 607 ◽

Cited By ~ 35

Author(s):

Shane T. Ahyong ◽

Christine Harling

Keyword(s):

Missing Data ◽

Cladistic Analysis ◽

The Other ◽

Crown Group ◽

Data Set ◽

Long Line ◽

Stem Lineage ◽

The Impact ◽

Hard Substrates ◽

Familial Classification

The stomatopods, or mantis shrimps, are malacostracan crustaceans of the subclass Hoplocarida. Extant hoplocarids belong to the order Stomatopoda and suborder Unipeltata, comprising the extinct, stem-lineage pseudosculdids and sculdids, and the crown group. Cladistic analysis including most or all genera of the unipeltatan families, and rooted to the extinct Tyrannophontidae, resulted in four most-parsimonious cladograms. The present results are more highly resolved and more robust than previous studies as the result of: more precise identification of suitable outgroups; a more complete outgroup data set, lessening the impact of missing data; and increased taxonomic sampling. The results largely support the existing five-superfamily classification, but as with two recent cladistic studies, Gonodactyloidea was polyphyletic. Gonodactyloidea is the basal crown-group superfamily and comprises mostly ‘smashers’. Two clades of ‘spearers’, Eurysquillidae and Parasquillidae, previously considered gonodactyloids, are more closely related to the Squilloidea and are referred to new superfamilies. The familial classification within Lysiosquilloidea is modified. Rather than deriving the ‘smashers’ from a long line of ‘spearers’, the present analysis suggests that the Unipeltata diverged in two broad directions from the outset. Hence, the gonodactyloid ‘smashers’ became specialised for hard substrates, and the remainder diversified into the other modern superfamilies, evolving more efficient ‘spearing’ claws, and occupying soft substrates.

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Ancient noeggerathialean reveals the seed plant sister group diversified alongside the primary seed plant radiation

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2013442118 ◽

2021 ◽

Vol 118 (11) ◽

pp. e2013442118

Author(s):

Jun Wang ◽

Jason Hilton ◽

Hermann W. Pfefferkorn ◽

Shijun Wang ◽

Yi Zhang ◽

...

Keyword(s):

Three Dimensional ◽

Cladistic Analysis ◽

Sister Group ◽

Seed Plants ◽

Vascular Bundles ◽

Seed Plant ◽

Stem Lineage ◽

Ash Deposit ◽

Plant Stem

Noeggerathiales are enigmatic plants that existed during Carboniferous and Permian times, ∼323 to 252 Mya. Although their morphology, diversity, and distribution are well known, their systematic affinity remained enigmatic because their anatomy was unknown. Here, we report from a 298-My-old volcanic ash deposit, an in situ, complete, anatomically preserved noeggerathialean. The plant resolves the group’s affinity and places it in a key evolutionary position within the seed plant sister group. Paratingia wuhaia sp. nov. is a small tree producing gymnospermous wood with a crown of pinnate, compound megaphyllous leaves and fertile shoots each with Ω-shaped vascular bundles. The heterosporous (containing both microspores and megaspores), bisporangiate fertile shoots appear cylindrical and cone-like, but their bilateral vasculature demonstrates that they are complex, three-dimensional sporophylls, representing leaf homologs that are unique to Noeggerathiales. The combination of heterospory and gymnospermous wood confirms that Paratingia, and thus the Noeggerathiales, are progymnosperms. Progymnosperms constitute the seed plant stem group, and Paratingia extends their range 60 My, to the end of the Permian. Cladistic analysis resolves the position of the Noeggerathiales as the most derived members of a heterosporous progymnosperm clade that are the seed plant sister group, altering our understanding of the relationships within the seed plant stem lineage and the transition from pteridophytic spore-based reproduction to the seed. Permian Noeggerathiales show that the heterosporous progymnosperm sister group to seed plants diversified alongside the primary radiation of seed plants for ∼110 My, independently evolving sophisticated cone-like fertile organs from modified leaves.

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Multi-Segmented Arthropods from the Middle Cambrian of British Columbia (Canada)

Journal of Paleontology ◽

10.1666/12-112.1 ◽

2013 ◽

Vol 87 (3) ◽

pp. 493-501 ◽

Cited By ~ 22

Author(s):

David Legg

Keyword(s):

British Columbia ◽

National Park ◽

Cladistic Analysis ◽

Sister Group ◽

Sister Group Relationship ◽

Crown Group ◽

Middle Cambrian ◽

New Family ◽

Stem Lineage ◽

Shale Formation

A new arthropod, Kootenichela deppi n. gen. n. sp., is described from the Stanley Glacier exposure of the middle Cambrian (Series 3, Stage 5) Stephen Formation in Kootenay National Park (British Columbia, Canada). This taxon possesses a number of primitive arthropod features such as an elongate, homonomous trunk (consisting of at least 29 segments), poorly sclerotised trunk appendages, and large pedunculate eyes associated with an anterior (ocular) sclerite. The cephalon encompasses a possible antenna-like appendage and enlarged raptorial appendages with a bipartite peduncle and three spinose distal podomeres, indicative of megacheiran (“great-appendage” arthropod) affinities. The relationships of megacheirans are controversial, with them generally considered as either stem-euarthropods or a paraphyletic stem-lineage of chelicerates. An extensive cladistic analysis resolved Kootenichela as sister-taxon to the enigmatic Worthenella cambria from the middle Cambrian (Series 3, Stage 5), Burgess Shale Formation in Yoho National Park (British Columbia), which is herein reinterpreted as a megacheiran arthropod. Based on their sister-group relationship, both taxa were placed in the new family Kootenichelidae, to which Pseudoiulia from the Chengjiang biota is also tentatively assigned. All of these taxa possess an elongate, multi-segmented body and subtriangular exopods. This family occupies a basal position within a paraphyletic Megacheira, the immediate outgroup of Euarthropoda (crown-group arthropods). The resultant topology indicates that analyses that have resolved megacheirans as stem-chelicerates have done so because they have rooted on inappropriate taxa, e.g., trilobitomorphs and marrellomorphs.

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Phylogenetic analysis of the Squilloidea (Crustacea:Stomatopoda)

Invertebrate Systematics ◽

10.1071/is04037 ◽

2005 ◽

Vol 19 (3) ◽

pp. 189 ◽

Cited By ~ 10

Author(s):

Shane T. Ahyong

Keyword(s):

Phylogenetic Analysis ◽

Late Cretaceous ◽

Cladistic Analysis ◽

West Pacific ◽

East Pacific ◽

Stem Lineage ◽

Familial Classification

Squilloidea is the most speciose of the stomatopod superfamilies and comprises more than 40 genera. Until 2001, three families were recognised: two extant (Harpiosquillidae, Squillidae) and one extinct (Ursquillidae). Recent studies, however, suggested that Harpiosquillidae is nested among other squillids and was thus synonymised with Squillidae. Interrelationships of all squilloid genera are studied by cladistic analysis based on somatic morphology. Results are used to assess the familial classification and investigate the ‘shape’ of squilloid evolution. The phylogeny of the squilloids shows general trends in the armature of the raptorial claw, increased dorsal carination, a tendency for bilobation of the lateral processes of the exposed thoracic somites, and a change in telson shape from trianguloid with movable submedian teeth, to quadriform with fixed submedian teeth. Harpiosquilla Holthuis, 1964 is deeply nested among other squillid genera, supporting the recent synonymy of the Squillidae and Harpiosquillidae. Characters of the late Cretaceous Ursquillidae show that it is highly derived and is therefore synonymised with Squillidae. Although the antiquity of Ursquilla Hof, 1998 does not show it to be a basal or stem-lineage squilloid, it does show that the squilloids had already undergone significant diversification by the end of the Cretaceous. Species of most squilloid genera are regionally restricted, either to the Indo-west Pacific or Atlanto-east Pacific. Only Alima Leach, 1818, Cloridopsis Manning 1968b, and Pontiosquilla Manning, 1995 are represented in both regions.

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Immunolabelling of glomerular deposits in kidney biopsies routinely fixed in glutaraldehyde

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100156535 ◽

1989 ◽

Vol 47 ◽

pp. 910-911

Author(s):

Ś Lhoták ◽

I. Alexopoulou ◽

G. T. Simon

Keyword(s):

Uv Light ◽

Kidney Diseases ◽

Light Chains ◽

Microscopical Level ◽

Accurate Identification ◽

Light Microscopical Level ◽

Dense Deposits ◽

Cacodylate Buffer ◽

Glomerular Deposits ◽

Prognostic Importance

Various kidney diseases are characterized by the presence of dense deposits in the glomeruli. The type(s) of immunoglobulins (Igs) present in the dense deposits are characteristic of the disease. The accurate Identification of the deposits is therefore of utmost diagnostic and prognostic importance. Immunofluorescence (IF) used routinely at the light microscopical level is unable to detect and characterize small deposits found in early stages of glomerulonephritis. Although conventional TEM is able to localize such deposits, it is not capable of determining their nature. It was therefore attempted to immunolabel at EM level IgG, IgA IgM, C3, fibrinogen and kappa and lambda Ig light chains commonly found in glomerular deposits on routinely fixed ( 2% glutaraldehyde (GA) in 0.1M cacodylate buffer) kidney biopsies.The unosmicated tissue was embedded in LR White resin polymerized by UV light at -10°C. A postembedding immunogold technique was employed

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Project BRAIN: Working Together to Improve Educational Outcomes for Students With Traumatic Brain Injury

Perspectives on Neurophysiology and Neurogenic Speech and Language Disorders ◽

10.1044/nnsld22.3.106 ◽

2012 ◽

Vol 22 (3) ◽

pp. 106-118 ◽

Cited By ~ 3

Author(s):

Paula Denslow ◽

Jean Doster ◽

Kristin King ◽

Jennifer Rayman

Keyword(s):

Traumatic Brain Injury ◽

At Risk ◽

Brain Injury ◽

Educational Outcomes ◽

School Personnel ◽

Department Of Education ◽

Health Providers ◽

Accurate Identification ◽

Transition Intervention ◽

Working Together

Children and youth who sustain traumatic brain injury (TBI) are at risk for being unidentified or misidentified and, even if appropriately identified, are at risk of encountering professionals who are ill-equipped to address their unique needs. A comparison of the number of people in Tennessee ages 3–21 years incurring brain injury compared to the number of students ages 3–21 years being categorized and served as TBI by the Department of Education (DOE) motivated us to create this program. Identified needs addressed by the program include the following: (a) accurate identification of students with TBI; (b) training of school personnel; (c) development of linkages and training of hospital personnel; and (d) hospital-school transition intervention. Funded by Health Services and Resources Administration (HRSA) grants with support from the Tennessee DOE, Project BRAIN focuses on improving educational outcomes for students with TBI through the provision of specialized group training and ongoing education for educators, families, and health professionals who support students with TBI. The program seeks to link families, hospitals, and community health providers with school professionals such as speech-language pathologists (SLPs) to identify and address the needs of students with brain injury.

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