scholarly journals Cranial ornamentation in the Late Cretaceous nodosaurid ankylosaurHungarosaurus

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11010
Author(s):  
Attila Ősi ◽  
János Magyar ◽  
Károly Rosta ◽  
Matthew Vickaryous
Keyword(s):  
Individual Differences ◽  
Sexual Dimorphism ◽  
Late Cretaceous ◽  
Sister Group ◽  
Ontogenetic Stage ◽  
Size Classes ◽  
Number Of Species ◽  
Interspecific Recognition

Bony cranial ornamentation is developed by many groups of vertebrates, including ankylosaur dinosaurs. To date, the morphology and ontogenetic origin of ankylosaurian cranial ornamentation has primarily focused on a limited number of species from only one of the two major lineages, Ankylosauridae. For members of the sister group Nodosauridae, less is known. Here, we provide new details of the cranial anatomy of the nodosauridHungarosaurusfrom the Santonian of Europe. Based on a number of previously described and newly identified fragmentary skulls and skull elements, we recognize three different size classes ofHungarosaurus. We interpret these size classes as representing different stages of ontogeny. Cranial ornamentation is already well-developed in the earliest ontogenetic stage represented herein, suggesting that the presence of outgrowths may have played a role in intra- and interspecific recognition. We find no evidence that cranial ornamentation inHungarosaurusinvolves the contribution of coossified osteoderms. Instead, available evidence indicates that cranial ornamentation forms as a result of the elaboration of individual elements. Although individual differences and sexual dimorphism cannot be excluded, the observed variation inHungarosauruscranial ornamentation appears to be associated with ontogeny.

Ostracoda from the Santonian–Campanian (Upper Cretaceous) Nenjiang and Sifangtai formations, Songliao Basin, northeastern China

2021 ◽  
pp. 1-23
Author(s):  
Yunqi Ye ◽  
Dangpeng Xi ◽  
Lixin Sun ◽  
Dermeval Aparecido Do Carmo ◽  
Lucas Silveira Antonietto ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Late Cretaceous ◽  
Upper Cretaceous ◽  
Northeastern China ◽  
Songliao Basin ◽  
Unique Material ◽  
China And Japan ◽  
Far Eastern

Abstract Despite the abundant literature on limnic Cretaceous ostracode faunas, the database on mid-Late Cretaceous taxa is still scarce. The Songliao Basin in northeastern China preserves a diverse assemblage of ostracode fossils from the Santonian–Campanian Nenjiang and Sifangtai formations. This rather unique material is of major importance to comprehend Early to mid-Late Cretaceous (Cenomanian–Campanian) limnic ostracode faunas and therefore the evolution of Late Cretaceous basins in China. A study of this fauna was conducted to detail the taxonomy of ostracode species from members 1 and 2 of the Nenjiang and Sifangtai formations in the Songliao Basin. Well-preserved specimens of 14 ostracode species were recovered from samples of the ZKY2-1 well in southwestern Songliao Basin: Scabriculocypris liaukhenensis Liu in Netchaeva et al., 1959, Ilyocyprimorpha netchaevae Su in Netchaeva et al., 1959, Cypridea acclinia Netchaeva in Netchaeva et al., 1959, Cypridea cavernosa Galeeva, 1955, Cypridea gracile Netchaeva in Netchaeva et al., 1959, Cypridea lepida Ye in DOFEAD, 1976, Cypridea squalida Sou in Netchaeva et al., 1959, Fabaeformiscandona? Disjuncta (Hao in Hao et al., 1974), Lycopterocypris profunda Lübimova, 1956, Mongolocypris magna (Hou, 1958), Mongolocypris tera (Su in Netchaeva et al., 1959), Talicypridea obliquecostae (Szczechura and Błaszyk, 1970), Talicypridea reticulata (Szczechura, 1978) and Renicypris renalata (Su in Hao et al., 1974). Four of the species identified received emended descriptions and diagnoses. Other important results include the first discussion on sexual dimorphism in Cypridea acclinia and Fabaeformiscandona? disjuncta, the first study on the ontogeny of Ilyocyprimorpha netchaevae, and the reassignment of Cypridea liaukhenensis to the genus Scabriculocypris. Several species recorded herein are also found in other continental far-eastern Asian basins, while genera range from worldwide to far-eastern Asian distribution; these results support strong affinities among faunas of Mongolia, China, and Japan.

scholarly journals Successional changes in epiphytic rainforest lichens: implications for the management of rainforest communities

2010 ◽  
Vol 42 (3) ◽  
pp. 311-321 ◽  
Author(s):  
Sharon E. MORLEY ◽  
Maria GIBSON
Keyword(s):  
Species Richness ◽  
Lichen Species ◽  
Size Classes ◽  
Number Of Species ◽  
Cool Temperate ◽  
Bark Texture ◽  
Old Trees ◽  
Temperate Rainforests ◽  
Stand Characteristics ◽  
Lichen Flora

AbstractWe explored lichen species richness and patterns of lichen succession on rough barked Nothofagus cunninghamii trees and on smooth barked Atherosperma moschatum trees in cool temperate rainforests in Victoria, Australia. Nothofagus cunninghamii trees from the Yarra Ranges, and A. moschatum trees from Errinundra were ranked into size classes (small, medium, large and extra-large), and differences in species richness and composition were compared between size classes for each tree species. Nothofagus cunninghamii supported a rich lichen flora (108 trees, 52 lichen species), with the largest trees supporting a significantly higher number of species, including many uncommon species. This success was attributed to varying bark texture, stand characteristics and microhabitat variations as the trees age. Atherosperma moschatum supported a comparable number of species (120 trees, 54 lichen species). Indeed on average, this host supported more lichen species than N. cunninghamii. However, successional patterns with increasing girth were not as clear for A. moschatum, possibly due to the more stable microclimate that this smooth barked host provided. Victorian cool temperate rainforests exist primarily as small, often isolated pockets within a sea of Eucalypt-dominated, fire-prone forest. Many are regenerating from past disturbance. We find that protection of Victoria's oldest rainforest pockets is crucial, as they represent sources of rare, potentially threatened lichen species, and may be acting as reservoirs for propagules for nearby ageing rainforests. Indeed, even single, large old trees have conservation importance, as they may provide exceptional microhabitats, not found elsewhere in the regenerating rainforest environment.

scholarly journals Arenysaurus ardevoli, first paleoneuroanatomical description of a European hadrosaurid

2014 ◽  
Author(s):  
Penélope Cruzado-Caballero ◽  
Josep Fortuny ◽  
Sergio Llacer ◽  
José Ignacio JI Canudo
Keyword(s):  
North America ◽  
Inner Ear ◽  
Late Cretaceous ◽  
Cerebral Hemisphere ◽  
3D Model ◽  
General Pattern ◽  
Semicircular Canals ◽  
Major Axis ◽  
Ontogenetic Stage ◽  
And Behavior

The neuroanatomy of hadrosaurid dinosaurs is well known from North America and Asia. In Europe only a few cranial remains have been recovered with the braincase. Arenysaurus is the first European endocast for which the paleoneuroanatomy has been studied. The resulting data have enabled us to draw ontogenetic, phylogenetic and functional inferences. Arenysaurus preserves the endocast and the inner ear. This cranial material was CT-scanned, and a 3D-model was generated. The endocast morphology supports a general pattern for hadrosaurids with some characters that distinguish to a subfamily level, such as a brain cavity anteroposteriorly shorter or the angle of the major axis of the cerebral hemisphere to the horizontal in lambeosaurines. Both characters are present in the endocast of Arenysaurus. Moreover, osteological features indicate an adult ontogenetic stage while some paleoneuroanatomical features are indicative of a subadult ontogenetic stage and even a juvenile ontogenetic stage. Finally, a comparison with other hadrosaurids reveals that the low values for the angle of the dural peak may be an autapomorphy exclusive to the Parasaurolophus genus. It is hypothesized that the presence of puzzling characters that suggest different ontogenetic stages for this specimen, may reflect some degree of dwarfism in Arenysaurus. Regarding the inner ear, its structure shows differences from the ornithopod clade with respect to the height of the semicircular canals. These differences could lead to a decrease in the compensatory movements of eyes and head, with important implications for the paleobiology and behavior of hadrosaurid taxa such as Edmontosaurus, Parasaurolophus and Arenysaurus. These differences in the vestibular system could be used as a phylogenetical signal. The endocranial morphology of European hadrosaurids sheds new light on the evolution of this group and may reflect the conditions in the archipelago where these animals lived during the Late Cretaceous.

Crozetia Davies (Diptera: Simuliidae): redescription of Cr. crozetensis, Cr. seguyi, number of larval instars, phylogenetic relationships and historical biogeography

Zootaxa ◽  
2003 ◽  
Vol 259 (1) ◽  
pp. 1 ◽  
Author(s):  
DOUGLAS A. CRAIG ◽  
DOUGLAS C. CURRIE ◽  
PHILIPPE VERNON
Keyword(s):  
Phylogenetic Analysis ◽  
Adult Female ◽  
Late Cretaceous ◽  
Morphometric Analysis ◽  
Phylogenetic Relationships ◽  
Sister Group ◽  
Historical Biogeography ◽  
Molecular Evidence ◽  
Early Eocene ◽  
Larval Instars

The taxonomy of the genus Crozetia Davies (Diptera: Simuliidae) is reviewed. Apart from the eggs, all stages of Crozetia crozetensis (Womersley) and Cr. seguyi Beaucournu-Saguez and Vernon, are fully redescribed with only claws and genitalia detailed for the female of Cr. crozetensis. A phylogenetic analysis of the Simuliidae indicates that Crozetia is the sister group of all other members of the extant Simuliini, in agreement with current molecular evidence. Palaeogeological evidence on the age of the Crozet Islands is equivocal, but a very late Cretaceous to early Eocene age (79-54 Mya) is most likely, hence the presence of simuliids on this archipelago is not the result of vicariance from Gondwanaland. Method of dispersal to the Crozet Archipelago may have been via wind or possibly vectored by birds from Africa, as suggested by presence of a basal tooth on the adult female claw. Morphometric analysis of larvae of Cr. seguyi indicates seven instars which is typical for the Simuliidae.

scholarly journals Origin and early evolution of Aves: dinosaurs, ancient birds, and mtDNA sequences

1992 ◽  
Vol 6 ◽  
pp. 267-267
Author(s):  
Paul C. Sereno
Keyword(s):  
Late Cretaceous ◽  
Dna Sequences ◽  
Lower Cretaceous ◽  
Wrist Joint ◽  
Sister Group ◽  
Avian Evolution ◽  
Mitochondrial Cytochrome B ◽  
History Of ◽  
Important Intermediate ◽  
Lake Deposits

Recently a general cladistic framework for early avian evolution has emerged. Postcranial modifications in the wrist joint and elsewhere firmly establish birds as a diversified subgroup of maniraptoran theropods. And the best known Mesozoic avians–Archaeopteryx and Late Cretaceous Hesperornis and Ichthyornis –have been positioned as successive sister taxa to living birds. Within this framework, however, several basic phylogenetic questions need to be addressed: (1) Which maniraptorans are most closely related to birds? (2) How was the modern avian skeleton built during the first third of avian history, between Archaeopteryx and Late Cretaceous Hesperornis and Ichthyornis? (3) And what are the relationships between the major groups of living birds?Avian origins. Synapomorphies listed by Ostrom and others to unite birds and other theropods typically apply to all maniraptorans or higher-level theropod clades, leaving unsettled the question of which maniraptorans constitute the immediate outgroups to birds. Deinonychosauria is confirmed as the sister-group to Aves, based principally on synapomorphies of the pectoral and pelvic girdles. In contrast to some previous suggestions, this study supports monophyly of Deinonychosauria (uniting dromaeosaurids and troodontids), with a single origin of the hyper-extendable, raptorial digit II of the pes.Sinornis and the evolution of powered flight and perching. Archaeopteryx lacks the profound modifications of the avian skeleton that characterize Ichthyornis and modern birds. Recent discovery of Lower Cretaceous birds has brought to light important intermediate stages in the transformation of the avian skeleton. Sparrow-sized Sinornis, discovered in Lower Cretaceous lake deposits in China, exhibits features that are associated with sustained powered flight; the laterally directed glenoid and V-shaped ulnare suggest that the wing was capable of tight flexion during flight. Features unrelated to the flight apparatus, in contrast, have not been altered; the skull is toothed, the manal digits are flexible and clawed, and gastralia are present beneath the rib cage.Higher-level relationships among living birds. The deep branching history of living birds occurred before the end of the Cretaceous and can be reconstructed from anatomical and genetic evidence in living birds. DNA sequences have been obtained from the mitochondrial cytochrome b gene in a variety of living birds. These data are consistent with a basal split between palaeognaths and neognaths and support the basal position of galliforms and anseriforms among neognaths. Piciforms appear to be closely related to passeriforms, and Corvida does not appear to be monophyletic, in contrast to recent DNA-DNA hybridization results.

Direct Observation of Sex Change in the Patellacean Limpet Lottia Gigantea

1982 ◽  
Vol 62 (3) ◽  
pp. 737-738 ◽  
Author(s):  
William G. Wright ◽  
David R. Lindberg
Keyword(s):  
Sexual Dimorphism ◽  
Differential Growth ◽  
External Fertilization ◽  
Size Classes ◽  
Direct Observations ◽  
Protandric Hermaphroditism ◽  
Intermediate Size ◽  
Lottia Gigantea ◽  
Male To Female ◽  
Simultaneous Hermaphrodites

Protandric hermaphroditism, the sequential change from male to female, has been reported in several superfamilies of prosobranch gastropods including the Fissurellacea, Patellacea, Calyptraeacea, and Eulimacea (Webber, 1977). It is most common in members of the Calyptraeacea and the Patellacea. In the Calyptraeacea changes in sex are readily followed by observing copulative structures (Coe, 1944). Because patellacean limpets are predominantly broadcast spawners with external fertilization, external characters that can be used to determine the sex of individuals are rare. Hence, previous to this report the occurrence of protandry in most patellacean limpets has been based primarily on sexual dimorphism in size; the smaller size classes being made up of male individuals and the larger size classes of female individuals (Willcox, 1898; Orton, 1920, 1928; Orton, Southward & Dodd, 1956; Dodd, 1956; Branch, 1974). However, given this type of data it is often difficult to assess whether the observed sexual dimorphism is indicative of protandry or merely a result of differential growth and/or survival. The presence of simultaneous hermaphrodites in the intermediate size classes, as evidence of protandry is of limited value because simultaneous hermaphrodites occur sporadically in patellaceans that do not show a sexual dimorphism in size (Dodd, 1956; Branch, 1974). The only unambiguous way of proving the existance of protandry in patellacean limpets is the direct monitoring of gonadal changes in individuals through time. We report here the first direct observations of protandric hermaphroditism in a patellacean limpet.Lottia gigantea Sowerby, 1834 is a large (100 + mm), territorial, intertidal limpet that ranges from northern California to central Baja California, Mexico (Stimson, 1970).

New Ancorabolidae (Copepoda: Harpacticoida) from Korea: two new genera, revisionary notes and updated identification keys

2019 ◽  
Vol 187 (2) ◽  
pp. 331-377 ◽  
Author(s):  
Jimin Lee ◽  
Rony Huys
Keyword(s):  
Sexual Dimorphism ◽  
Korean Peninsula ◽  
Posterior Margin ◽  
Sister Group ◽  
Sister Taxon ◽  
Copepod Species ◽  
New Genera ◽  
The Family ◽  
The One ◽  
Species Inquirendae

Abstract Two new copepod species of the Ceratonotus group in the subfamily Ancorabolinae (Ancorabolidae) are described from the Korean peninsula. Dendropsyllus kimi sp. nov. differs from its congeners by the one-segmented ♀ P3 endopod, the inner spine on ♀ P5 exopod and the absence of sensillate tubercles on abdominal somites 1 and 2. Dimorphipodia gen. nov. is proposed to accommodate Dimorphipodia changi sp. nov. and can be differentiated from its sister taxon, Arthuricornua, by the sexual dimorphism in P2–P4 exp-3, the absence of paired laterodorsal processes near the posterior margin of the cephalothorax and the presence of pleural setular tufts on somites bearing P2–P4. Ancorabolina, previously placed in the Ancorabolinae, is transferred to the Laophontodinae, whereas Patagoniaella is provisionally reassigned to the family Cletodidae. Within Laophontodes, the inadequately described Laophontodes brevis, Laophontodes ornatus and Laophontodes propinquus are relegated to species inquirendae. Laophontodes georgei sp. nov. is proposed for the unavailable name Laophontodes norvegicus, Laophontodes multispinatus is reassigned to Lobopleura, and Laophontodes gracilipes is fixed as the type of Rostrophontodes gen. nov., the potential sister group of Ancorabolina. The authenticity of Laophontodes bicornis and other dubious ancorabolid records from the Korean peninsula is discussed. Updated keys to genera of both Ancorabolinae and Laophontodinae and to species of Laophontodes are provided.

scholarly journals Temporal shifts in ostracode sexual dimorphism from the Late Cretaceous to the late Eocene of the U.S. Coastal Plain

2021 ◽  
pp. 101959
Author(s):  
Maya Samuels-Fair ◽  
Maria João Fernandes Martins ◽  
Rowan Lockwood ◽  
John P. Swaddle ◽  
Gene Hunt
Keyword(s):  
Sexual Dimorphism ◽  
Late Cretaceous ◽  
Coastal Plain ◽  
Late Eocene ◽  
The U.S ◽  
Temporal Shifts

scholarly journals A new genus of Buchonomyiinae (Diptera, Chironomidae) from Late Cretaceous Burmese amber, with the phylogeny of the subfamily revisited.

2017 ◽  
Author(s):  
Viktor Baranov
Keyword(s):  
Late Cretaceous ◽  
New Genus ◽  
Single Species ◽  
Sister Group ◽  
Biting Midges ◽  
Fossil Species ◽  
Burmese Amber ◽  
Basal Group ◽  
Caddisfly Larvae ◽  
Dated Phylogeny

Among the eleven modern subfamilies of non-biting midges (Diptera: Chironomidae), Buchonomyiinae are the most primitive and considered to be the sister group to the rest of the chironomids. The subfamily is monotypic with a single genus Buchonomyia, including three Recent species from Europe, South-East Asia and Central America, and a single fossil species, B. succinea Seredszus and Wichard, 2002, from Baltic amber. The elusive nature of the larvae and pupae, who develop as parasites or are commensal of caddisfly larvae, means that records of recent Buchonomyiinae extremely rare. From the latest dated phylogeny of the Chironomidae, the Buchonomyiinae branched from the rest of the Chironomidae in the Early to Middle Jurassic. Here we present the oldest record of the subfamily Buchonomyiinae, from Late Cretaceous Burmese amber. The record is represented by a new genus Furcobuchonomyia, with a single species F. saetheri. Bayesian analysis firmly places the new genus as the sister group to the rest of the Buchonomyiinae. Thus the discovery of this genus is sheding new light on the origin of the most basal group of the Chironomidae. A species level key to the subfamily is included.

scholarly journals New skull material of Pleistocene dwarf deer from Crete (Greece)

2021 ◽  
Author(s):  
Ann-Marie SCHILLING ◽  
Gertrud E. RÖSSNER
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Skeletal Morphology ◽  
Number Of Species ◽  
Fossil Site ◽  
Respective Species

In the Pleistocene faunas of the island of Crete, Cervidae was one of the most abundant taxa. Respective species vary in body size, including dwarfs, and skeletal morphology; however, the number of species and the identity of the mainland ancestor(s) are still debated. In this paper, we morphologically and morpho­metrically describe and analyze eight skulls of Cretan deer from a so far little known fossil site near Gerani, Rethymnon, Greece. The recorded character suite allows for affiliation to dwarfed Candiacervus Kuss, 1975, Candiacervus ropalophorus de Vos, 1984 and C. reumeri van der Geer, 2018. It comprises previously unknown unique traits, some of them hinting to sexual dimorphism. Comparisons of the Candiacervus skulls presented here with those of cervids belonging to Megalocerotini Brooke, 1828, s.s. and s.l. stress certain similarities; yet more material is needed to reconstruct Candiacervus’ phylo­genetic position. The newly detected craniodental specifics allow for more insights into island adaptation of Candiacervus; at the same time, they blur the morphological heritage of their mainland ancestors.

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