Macroevolutionary patterns in cranial and lower jaw shape of ceratopsian dinosaurs (dinosauria, ornithischia). phylogeny, morphological integration, and evolutionary rates

Organisms: Ceratopsians were herbivorous, beaked dinosaurs, ranging from 1 m to 9 m in body length, usually four-footed, and with a bony frill that extended backwards from the cranium over the nape of the neck. Known from Asia, Europe, and North America, they appeared in the Late Jurassic and persisted until the end of the Late Cretaceous. Questions: Which evolutionary processes drive the phenotypic evolution of skulls and lower jaws within Ceratopsia? What is the degree of morphological integration between the skull and lower jaw, and between the snout and frill among clades? Finally, are there any morphological evolution rate shifts across the ceratopsian phylogeny? Data: Photographs from 121 ceratopsian skulls and 122 lower jaws in lateral view, both from original photos and published pictures. Fifty-five ceratopsian species are represented in the sample. Methods: We investigated cranial and lower jaw shape changes across ceratopsians applying two-dimensional geometric morphometrics. We also investigated the morphological variation of the snout and the frill. Using phylogenetic generalized least squares regression, we estimated the degree of phylogenetic signal in size and shape data, as well as in the shape-size relationship. We performed phenotypic evolutionary rate analysis on shape data to describe phenotypic shifts across the phylogeny. Using a rarefied version of Escoufier's RV coefficient, we tested morphological integration between skulls and lower jaws, and between snouts and frills. Finally, we explored the potential link between cranial and frill shape evolution in ceratopsians and the radiation of angiosperms using a linear regression model. Results: Skull, snout, and frill shapes differ among clades (with the exception of leptoceratopsids and protoceratopsids). Lower jaws show distinct morphologies among groups. Size and shape changes are phylogenetically structured. The frill drives the morphological variation of the skull, co-varying much more with the lower jaw than with the snout. The frill appears to evolve to co-vary better with the lower jaw in the more morphologically derived clades than in basal ones. A significant linear relationship does exist between cranial shape and angiosperm occurrences, suggesting the hypothesis that the frill evolved in response to changes in dietary compositions associated with the turnover between gymnosperms and angiosperms during the Cretaceous. Significant negative shifts in evolutionary rates characterize skull, snout, frill, and lower jaw shapes, corresponding to nodes where psittacosaurids diverge from other taxa. In contrast, a significant positive shift in skull and snout shape rate of evolution characterizes the clade Ceratopsoidea. Conclusion: The frill is the main driving force in the overall cranial shape within Ceratopsia and evolved secondarily to better co-vary with the lower jaw to produce a more efficient masticatory apparatus. The changes in frill shape are correlated with the angiosperm diversification that occurred in the Cretaceous and thus correlated with changes in diet. Ceratopsians exhibit a slowdown in the phenotypic evolutionary rate in the Early Cretaceous and an acceleration of the phenotypic rate in the Late Cretaceous

Males resemble females. re-evaluating sexual dimorphism in protoceratops andrewsi (neoceratopsia, protoceratopsidae)

BACKGROUND: Protoceratops andrewsi (Neoceratopsia, Protoceratopsidae) is a well-known dinosaur from the Upper Cretaceous of Mongolia. Some previous workers hypothesized sexual dimorphism in the cranial shape of this taxon, using qualitative and quantitative observations. In particular, width and height of the frill as well as the development of a nasal horn have been hypothesized as potentially sexually dimorphic. METHODOLOGY/PRINCIPAL FINDINGS: Here, we reassess potential sexual dimorphism in skulls of Protoceratops andrewsi by applying two-dimensional geometric morphometrics to 29 skulls in lateral and dorsal views. Principal Component Analyses and nonparametric MANOVAs recover no clear separation between hypothetical "males" and "females" within the overall morphospace. Males and females thus possess similar overall cranial morphologies. No differences in size between "males" and "females" are recovered using nonparametric ANOVAs. CONCLUSIONS/SIGNIFICANCE: Sexual dimorphism within Protoceratops andrewsi is not strongly supported by our results, as previously proposed by several authors. Anatomical traits such as height and width of the frill, and skull size thus may not be sexually dimorphic. Based on PCA for a data set focusing on the rostrum and associated ANOVA results, nasal horn height is the only feature with potential dimorphism. As a whole, most purported dimorphic variation is probably primarily the result of ontogenetic cranial shape changes as well as intraspecific cranial variation independent of sex

Leitfaden für die praktische Umsetzung einer Freilandhaltung von Mastschweinen

EINLEITUNG: Dieser Leitfaden soll Hilfestellung beim Aufbau einer Freilandhaltung von Mastschweinen geben. Hinweise und Angaben basieren auf Erfahrungen aus einem Forschungsvorhaben mit Mastschweinen, das von Herbst 2002 bis Ende 2003 an der Universität Kassel / Witzenhausen auf dem Versuchsbetrieb der Hessischen Staatsdomäne Frankenhausen durchgeführt wurde. Des Weiteren fließen Erfahrungen von Freilandschweinehaltern ein, die im Rahmen einer Diplomarbeit befragt wurden, sowie Angaben aus der Literatur ein. Die Freilandhaltung bietet die Möglichkeit, mit geringen Investitionskosten eine artgemäße Schweinehaltung zu verwirklichen, die sich auch in die pflanzliche Erzeugung integrieren lässt. Die erste Voraussetzung für die Einrichtung einer Freilandhaltung sollten jedoch nicht in erster Linie finanzielle Überlegungen sein, sondern die eigene Bereitschaft, 365 Tage im Jahr die Tiere im Freien zu betreuen. Verfahren, bei denen Schweine erst im März aufgestallt werden und der letzte Durchgang im November endet, sind natürlich möglich, wenn alle Tiere als Ferkel zugekauft werden. INHALT: 1 Einleitung 2 Gesetzliche Vorgaben 2.1 Schweinehaltungshygieneverordnung (SchHaltHygV) 2.2 Verordnungen für die Ökologische Landwirtschaft 2.2.1 EG-Verordnung (EWG) Nr. 2092/91 2.2.2 Richtlinien von deutschen Öko-Verbänden 3 Durchführung einer Freilandhaltung von Mastschweinen 3.1 Standorteignung 3.2 Flächengestaltung 3.3 Einrichtung für eine Schweinehaltung im Freiland 3.3.1 Zaun 3.3.2 Schutzhütte 3.3.3 Wassertränke 3.3.4 Futtertrog 3.3.5 Suhle 3.3.6 Schattendach 3.4 Tierherkunft 3.5 Fütterung mit Kraftfutter 3.6 Umgang mit den Tieren Anhang Tägliche Futtermenge pro Tie

Ganzjährige Freilandhaltung von Mastschweinen als ein Fruchtfolgeglied im Ökologischen Landbau

In einem Freilandversuch mit Mastschweinen wurden drei genetische Herkünfte (Ha x Pi) x (Du x DL), Pi x (DE x DL) und Pi x (Du x DL) auf verschiedenen Futterflächen mit Stoppelrübe, Weidelgras, Topinambur und Getreidestoppeln gehalten. Die Menge an Konzentratfutter variierte in Abhängigkeit von den angebotenen Früchten und der Jahreszeit. Die Tiere zeigten mit 740g gute mittlere Tageszunahmen und wiesen mittlere Muskelfleischanteile von 54 bis 56 % auf. Unterschiede zwischen den mittleren Tageszunahmen bestanden vor allem zwischen den Genotypen, während Unterschiede zwischen den mittleren Muskelfleischanteilen maßgeblich auf die Varianten zurückgeführt werden konnten. Die Produktions- und Schlachtleistungen der Tiere, die während der Endmastphase Flächen mit Topinamburbewuchs beweideten, zeigten, dass durch Topinambur ein hohes Nährstoffpotential auf den Flächen vorhanden und auch von den Schweinen nutzbar war. Reine Kraftfutterrationen hatten einen hohen Austrag von N und P in den Boden zur Folge, der höher lag als unter den ökologischen Rahmenbedingungen zulässig. Durch Umsetzen der Versorgungseinheiten (Hütten, Futtertröge und Tränken) konnten die punktuellen Nährstoffkonzentrationen in diesen Bereichen deutlich reduziert werden. Eine Portionsbeweidung erhöhte die Attraktivität der Auslaufflächen und hatte eine gleichmäßigere Verteilung der Nährstoffe zur Folge. Aus den Ergebnissen wird geschlussfolgert, dass in der Mastschweinehaltung unter Freilandbedingungen ein akzeptables Leistungsniveau erreicht werden kann. Der Einsatz von Konzentratfutter kann durch Angebot von Ackerfrüchten deutlich reduziert werden. Durch ein optimiertes Management können negative Umwelteinflüsse vermieden bzw. auf ein tolerierbares Maß begrenzt werden

Suturen und Synchondrosen am Hundeschädel : ein Vergleich meso- und brachycephaler Rassen mittels Magnetresonanztomographie, Computertomographie und Histologie

Konventionelle Bildgebungsverfahren (MRT und CT) sind nützlich zur Bestimmung des “offenen” oder “geschlossenen” Status der Synchondrosen innerhalb der Schädelbasis. Der Schluss der Suturen ist in beiden Verfahren schwieriger zu erfassen, die Beurteilbarkeit hängt insbesondere beim MRT vom Erfahrungsmaß des Untersuchers ab. Die Histologie bietet eine eindeutige Aussage über den Status der Sutur und sollte somit als Goldstandard angesehen werden. Bezüglich der strukturellen Entwicklungen der Suturen bestätigen unsere Daten die Ergebisse anderer Studien aus der Humanmedizin, in denen normale Vorgänge des Fugenschlusses im Falle von Craniosynostosen und somit ggf. auch im Falle brachycephaler Rassen, zu früh erfolgen. Des Weiteren bestehen Hinweise auf einen Zusammenhang zwischen der praematuren Fusion von Suturen bei brachycephalen Hunderassen und der Ausbildung einer Ventriculomegalie als auch einer Chiari-ähnlichen Malformation.Conventional imaging techniques are very useful to assess the open or closed status of synchondroses within the cranial base. Sutural closure is difficult to diagnose in MRI and CT. Assessment is dependent on observer experience. Histology has to be seen as the gold standard for suture assessment. Concerning structural suture development our data are confirming studies from human medicine indicating normal sutural closing patterns which occur simply to early in craniosynostosis and possibly in brachycephalic breeds. Furthermore there is evidence for an association between ventriculomegaly and Chiari-like malformation in brachycephalic breeds and premature fusion of different sutures

Differential expression of ABC transporters and their regulatory genes during lactation and dry period in bovine mammary tissue

ATP-binding cassette (ABC) transporters play a pivotal role in human physiology, and mutations in these genes often result in severe hereditary diseases. ABC transporters are expressed in the bovine mammary gland but their physiological role in this organ remains elusive. Based on findings in the context of human disorders we speculated that candidate ABC transporters are implicated in lipid and cholesterol transport in the mammary gland. Therefore we investigated the expression pattern of selected genes that are associated with sterol transport in lactating and nonlactating mammary glands of dairy cows. mRNA levels from mammary gland biopsies taken during lactation and in the first and second week of the dry period were analysed using quantitative PCR. Five ABC transporter genes, namely ABCA1, ABCA7, ABCG1, ABCG2 and ABCG5, their regulating genes LXRα, PPARγ, SREBP1 and the milk proteins lactoferrin and α-lactalbumin were assessed. A significantly enhanced expression in the dry period was observed for ABCA1 while a significant decrease of expression in this period was detected for ABCA7, ABCG2, SREBP1 and α-lactalbumin. ABCG1, ABCG5, LXRα, PPARγ and lactoferrin expression was not altered between lactation and dry period. These results indicate that candidate ABC transporters involved in lipid and cholesterol transport show differential mRNA expression between lactation and the dry period. This may be due to physiological changes in the mammary gland such as immigration of macrophages or the accumulation of fat due to the loss of liquid in the involuting mammary gland. The current mRNA expression analysis of transporters in the mammary gland is the prerequisite for elucidating novel molecular mechanisms underlying cholesterol and lipid transfer into mil

Ontogeny in the tube-crested dinosaur Parasaurolophus (Hadrosauridae) and heterochrony in hadrosaurids

The tube-crested hadrosaurid dinosaur Parasaurolophus is remarkable for its unusual cranial ornamentation, but little is known about its growth and development, particularly relative to well-documented ontogenetic series for lambeosaurin hadrosaurids (such as Corythosaurus, Lambeosaurus, and Hypacrosaurus). The skull and skeleton of a juvenile Parasaurolophus from the late Campanian-aged (∼75.5 Ma) Kaiparowits Formation of southern Utah, USA, represents the smallest and most complete specimen yet described for this taxon. The individual was approximately 2.5 m in body length (∼25% maximum adult body length) at death, with a skull measuring 246 mm long and a femur 329 mm long. A histological section of the tibia shows well-vascularized, woven and parallel-fibered primary cortical bone typical of juvenile ornithopods. The histological section revealed no lines of arrested growth or annuli, suggesting the animal may have still been in its first year at the time of death. Impressions of the upper rhamphotheca are preserved in association with the skull, showing that the soft tissue component for the beak extended for some distance beyond the limits of the oral margin of the premaxilla. In marked contrast with the lengthy tube-like crest in adult Parasaurolophus, the crest of the juvenile specimen is low and hemicircular in profile, with an open premaxilla-nasal fontanelle. Unlike juvenile lambeosaurins, the nasal passages occupy nearly the entirety of the crest in juvenile Parasaurolophus. Furthermore, Parasaurolophus initiated development of the crest at less than 25% maximum skull size, contrasting with 50% of maximum skull size in hadrosaurs such as Corythosaurus. This early development may correspond with the larger and more derived form of the crest in Parasaurolophus, as well as the close relationship between the crest and the respiratory system. In general, ornithischian dinosaurs formed bony cranial ornamentation at a relatively younger age and smaller size than seen in extant birds. This may reflect, at least in part, that ornithischians probably reached sexual maturity prior to somatic maturity, whereas birds become reproductively mature after reaching adult size

First Known Feeding Trace of the Eocene Bottom-Dwelling Fish Notogoneus osculus and Its Paleontological Significance

BACKGROUND: The Green River Formation (early Eocene, about 42-53 Ma) at and near Fossil Butte National Monument in Wyoming, USA, is world famous for its exquisitely preserved freshwater teleost fish in the former Fossil Lake. Nonetheless, trace fossils attributed to fish interacting with the lake bottom are apparently rare, and have not been associated directly with any fish species. Here we interpret the first known feeding and swimming trace fossil of the teleost Notogoneus osculus Cope (Teleostei: Gonorynchidae), which is also represented as a body fossil in the same stratum. METHODOLOGY/PRINCIPAL FINDINGS: A standard description of the trace fossil, identified as Undichna cf. U. simplicatas, was augmented by high-resolution digital images and spatial and mathematical analyses, which allowed for detailed interpretations of the anatomy, swimming mode, feeding behavior, and body size of the tracemaker. Our analysis indicates that the tracemaker was about 45 cm long; used its caudal, anal, and pelvic fins (the posterior half of its body) to make the swimming traces; and used a ventrally oriented mouth to make overlapping feeding marks. We hypothesize that the tracemaker was an adult Notogoneus osculus. CONCLUSIONS/SIGNIFICANCE: Our results are the first to link a specific teleost tracemaker with a trace fossil from the Green River Formation, while also interpreting the size and relative age of the tracemaker. The normal feeding and swimming behaviors indicated by the trace fossil indicate temporarily oxygenated benthic conditions in the deepest part of Fossil Lake, counter to most paleoecological interpretations of this deposit. Lastly, our spatial and mathematical analyses significantly update and advance previous approaches to the study of teleost trace fossils

Evidence of Combat in Triceratops

Background: The horns and frill of Triceratops and other ceratopsids (horned dinosaurs) are interpreted variously as display structures or as weapons against conspecifics and predators. Lesions (in the form of periosteal reactive bone, healing fractures, and alleged punctures) on Triceratops skulls have been used as anecdotal support of intraspecific combat similar to that in modern horned and antlered animals. If ceratopsids with different cranial morphologies used their horns in such combat, this should be reflected in the rates of lesion occurrence across the skull. Methodology/Principal Findings: We used a G-test of independence to compare incidence rates of lesions in Triceratops (which possesses two large brow horns and a smaller nasal horn) and the related ceratopsid Centrosaurus (with a large nasal horn and small brow horns), for the nasal, jugal, squamosal, and parietal bones of the skull. The two taxa differ significantly in the occurrence of lesions on the squamosal bone of the frill (P = 0.002), but not in other cranial bones (P.0.20). Conclusions/Significance: This pattern is consistent with Triceratops using its horns in combat and the frill being adapted as a protective structure for this taxon. Lower pathology rates in Centrosaurus may indicate visual rather than physical use o