scholarly journals Dinosaur behavior and growth

1992 ◽  
Vol 6 ◽  
pp. 135-135 ◽  
Author(s):  
John R. Horner
Keyword(s):  
Upper Cretaceous ◽  
Social Behaviors ◽  
Mate Recognition ◽  
Morphological Evidence ◽  
First Year ◽  
Adult Size ◽  
Metabolic Rates ◽  
Paleontological Data ◽  
Sexual Display

Geological and paleontological data derived from the Upper Cretaceous Two Medicine Formation of Montana indicates that at least some dinosaur species exhibited complex social behaviors comparable to many living birds. Two species of duck-billed dinosaurs, a hypsilophodontid and a troodontid, nested in colonies and attended their respective young. Duckbilled dinosaurs had altricial young, whereas the hypsilophodontid and troodontid had precocial young. Morphological evidence indicates that several of the cranial elements of the nestling duckbills experienced retarded development, and a retention of juvenile features. Following their respective nesting periods duck-billed and horned dinosaurs aggregated into large herds, and apparently migrated seasonally. Cranial ornamentations possessed by duck-billed and horned dinosaurs were most likely used for sexual display and mate recognition.Osteohistological data indicates that the duck-billed dinosaurs hatched from their eggs at .50 to .75 meters in length, and exited their nests at 1.5 to 2 meters in length, at an age of about one month. These dinosaurs reached 3 to 4 meters in length their first year, and 7 to 8 meters in length after about 5 years. Growth and metabolic rates decreased substantially upon reaching adult size.

Reproductive biology of the parsley frog, Pelodytes punctatus, at the northernmost part of its range

1993 ◽  
Vol 14 (2) ◽  
pp. 131-147 ◽  
Author(s):  
M. Ohm ◽  
A.G. Toxopeus ◽  
J.W. Arntzen
Keyword(s):  
Reproductive Biology ◽  
Breeding Season ◽  
Adult Population ◽  
First Year ◽  
Adult Size ◽  
Dune System ◽  
Population Size Estimates ◽  
Coastal Dune System ◽  
Source Sink ◽  
Second Period

AbstractThe reproductive biology and population dynamics of Pelodytes punctatus were studied at the breeding season over a three year period in a coastal dune system located at the extreme northwestern border of the species' range. Adult population size estimates ranged from about 100 in the first year to 60 in the third year. Males were remarkably sedentary near the pond under artificially provided shelters. Many were observed during the most of the breeding season which lasted from mid-March or the end of March to the end of April or mid-May. Most spawning took place in the second half of March or early April. In two years out of three a second period of spawning involving fewer animals was observed in the first half of May. Both periods of spawning coincided with, or shortly followed, periods of rising median air temperature. Egg-clutches were deposited in the deepest parts of pond, mainly on submerged vegetation not reaching the surface. An average sized clutch contained approximately 360 eggs. Development of the embryos until hatching took from 4 to 14 days, depending on the ambient temperature. Larval development and growth were fast. Recently metamorphosed froglets at a size of around 18 mm were found from the end of May onwards. Juveniles may reach adult size in the autumn of the year that they were born. Adult frogs did not show a strong fidelity to the breeding pond between years. In the study area the population structure of Pelodytes punctatus seems to be best described by a source - sink model in which flourishing populations in the dunes give rise to short lived satellite populations outside the dunes.

Miroblatta baai, a new very large cockroach species from caves of Borneo (Blattaria: Blaberidae)

Zootaxa ◽  
2007 ◽  
Vol 1390 (1) ◽  
pp. 21 ◽  
Author(s):  
PHILIPPE GRANDCOLAS ◽  
LOUIS DEHARVENG
Keyword(s):  
New Species ◽  
River System ◽  
Morphological Evidence ◽  
Adult Size ◽  
Genital Morphology ◽  
East Kalimantan ◽  
The Family ◽  
Underground River ◽  
A New Species

A new species of the genus Miroblatta Shelford, 1906 is described from caves of Borneo in East Kalimantan, Indonesia. This new species, M. baai sp. nov., is similar to the epigean species M. petrophila Shelford, 1906 also found in Borneo. It differs by a larger adult size, longer legs, shorter wings, longer pronotum showing a remarkable central bulbous structure, lighter colouration and genital morphology (especially sclerite L1 shape). The genital morphology as well as morphological evidence for ovoviviparity confirm that the genus belongs to the family Blaberidae, subfamily Epilamprinae. Contrary to its epigean relative M. petrophila, this new species has been found exclusively in karstic caves of the same underground river system and these occurrences as well as the elongated legs and reduced eyes allow one to assume that this is a truly troglobitic species, so far the first one recorded in the family Blaberidae.

Tyrannosauroid dinosaurs from the Aguja Formation (Upper Cretaceous) of Big Bend National Park, Texas

2012 ◽  
Vol 103 (3-4) ◽  
pp. 471-485 ◽  
Author(s):  
Thomas M. Lehman ◽  
Steven L. Wick
Keyword(s):  
National Park ◽  
Upper Cretaceous ◽  
Frontal Bone ◽  
Adult Size ◽  
Unique Combination ◽  
Big Bend National Park ◽  
West Texas ◽  
Big Bend ◽  
Large Predators ◽  
Sagittal Crest

ABSTRACTRare remains of tyrannosauroid dinosaurs from the Aguja Formation in West Texas indicate the presence here of a relatively gracile species, comparable in form and adult size to Appalachiosaurus or subadult albertosaurines, Gorgosaurus and Albertosaurus. Histologic analysis of one of the specimens indicates that the Aguja tyrannosaur attained an adult size substantially smaller than adult albertosaurines (700 kg, 6·5 m body length). The frontal bone is narrow with a wide orbital slot and a bipartite joint for the postorbital, features thought to be diagnostic of Albertosaurinae; but there is a tall sagittal crest and reduced parietal wedge separating the frontals on the midline, features thought to be diagnostic of Tyrannosaurinae. The tall sagittal crest may be a synapomorphy of Tyrannosaurinae, and the Aguja tyrannosaur is herein referred to that clade. However, the unique combination of character states exhibited by the frontal prevents confident attribution to any known species. The Aguja tyrannosaur provides further evidence that North American Campanian tyrannosauroids were remarkably diverse for such large predators, and that each species was apparently endemic to a relatively small geographic province.

Bonebed amber as a new source of paleontological data: The case of the Pipestone Creek deposit (Upper Cretaceous), Alberta, Canada

2020 ◽  
Vol 81 ◽  
pp. 378-389 ◽  
Author(s):  
Pierre Cockx ◽  
Ryan McKellar ◽  
Ralf Tappert ◽  
Matthew Vavrek ◽  
Karlis Muehlenbachs
Keyword(s):  
Upper Cretaceous ◽  
Paleontological Data

Paleomagnetism of the Upper Cretaceous Nanaimo Group, southwestern Canadian Cordillera

2001 ◽  
Vol 38 (10) ◽  
pp. 1403-1422 ◽  
Author(s):  
Randolph J Enkin ◽  
Judith Baker ◽  
Peter S Mustard
Keyword(s):  
British Columbia ◽  
North America ◽  
Upper Cretaceous ◽  
Vertical Axis ◽  
Vancouver Island ◽  
Canadian Cordillera ◽  
Paleontological Data ◽  
The Mean ◽  
Prime Target

The Baja B.C. model has the Insular Superterrane and related entities of the Canadian Cordillera subject to >3000 km of northward displacement with respect to cratonic North America from ~90 to ~50 Ma. The Upper Cretaceous Nanaimo Group (on and about Vancouver Island, British Columbia) is a prime target to test the model paleomagnetically because of its locality and age. We have widely sampled the basin (67 sites from seven islands spread over 150 km, Santonian to Maastrichtian age). Most samples have low unblocking temperatures (<450°C) and coercivities (~10 mT) and strong present-field contamination, forcing us to reject three quarters of the collection. Beds are insufficiently tilted to provide a conclusive fold test, and we see evidence of relative vertical axis rotations. However, inclination-only analysis indicates pretilting remanence is preserved for many samples. Both polarities are observed, and reversals correlate well to paleontological data, proving that primary remanence is observed. The mean inclination, 55 ± 3°, is 13 ± 4° steeper than previously published results. Our new paleolatitude, 35.7 ± 2.6° is identical to that determined from the slightly older Silverquick and Powell Creek formations at Mount Tatlow, yet the inferred displacement is smaller (2300 ± 400 km versus 3000 ± 500 km) because North America was drifting southward starting around 90 Ma. The interpreted paleolatitude conflicts with sedimentologic and paleontologic evidence that the Nanaimo Basin was deposited near its present northern position.

Estimate of the population structure of the estern water dragon, Physignathus lesueurii (Reptilia : Agamidae), along riverside habitat

1993 ◽  
Vol 20 (5) ◽  
pp. 613 ◽  
Author(s):  
MB Thompson
Keyword(s):  
New South ◽  
Average Distance ◽  
First Year ◽  
Adult Size ◽  
Adult Males ◽  
Male Adult ◽  
Adult Females ◽  
South Wales ◽  
Size Growth ◽  
Theoretical Considerations

A population of eastern water dragons, Physignathus lesueurii, was investigated along 1.5km of the Gloucester River in central eastern New South Wales from November 1989 to December 1992. Dragons were caught in all months from September to April, but not in June. In all, 373 dragons were marked and 69 of these were recaptured on one or more occasions. Females are ovigarous in late October, November and December. Only about one third of females have palpable eggs during these months. Hatchlings enter the population in February and March at 4.5g, with a snout-vent length (SVL) of 53mm. In the next season they are 19.5g (SVL 80mm). The dragons grow rapidly for four years to reach adult size. Growth rates are fastest during the first year at 2.25mm SVL per month or 1.25 g per month. The Jolley-Seber population estimate for adult females was 103 +/-49 in the study site or 69 per km of river. Estimates for males and for the total population could not be calculated because individuals were not equally catchable (Leslie's test for equal catchability). However, theoretical considerations place the density of adult dragons at 138-215 per km of river. The largest male was 304mm SVL, 54mm longer than the next-largest water dragon reported. One male was heavier than 1000g. The largest female was 230mm SVL and the heaviest was 490g, or approximately half the mass of the heaviest male. Adult males and adult females have the same proportion of broken tails. Water dragons are fairly sedentary, with an average distance of 76m (range 0-785m) between captures.

scholarly journals Intriguing and Beautiful: Adamacrocera adami gen. et sp. nov. from the Upper Cretaceous Amber of Myanmar Represents a New Subfamily of Keroplatidae (Diptera: Bibionomorpha)

Insects ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 552
Author(s):  
Jan Ševčík ◽  
Wiesław Krzemiński ◽  
Kornelia Skibińska
Keyword(s):  
Upper Cretaceous ◽  
New Genus ◽  
Morphological Evidence ◽  
Wing Venation ◽  
Burmese Amber ◽  
Incertae Sedis ◽  
Fossil Genus

A new fossil genus and species of Keroplatidae (Diptera, Bibionomorpha, Sciaroidea), Adamacrocera adami gen. et sp. nov., from the Upper Cretaceous Burmese amber is described and illustrated. Based on morphological evidence, it is placed in a new subfamily Adamacrocerinae subfam. nov. The new genus, as well as the subfamily, possesses the wing venation characteristic of the genera of some Sciaroidea incertae sedis, as well as that of the fossil families Archizelmiridae, Antefungivoridae and Mesosciophilidae, in combination with macrocerine-like habitus and male terminalia.

scholarly journals Immunocompetence and high metabolic rates enhance overwinter survival in the root vole, Microtus oeconomus

2014 ◽  
Vol 10 (12) ◽  
pp. 20140684 ◽  
Author(s):  
Aneta Książek ◽  
Karol Zub ◽  
Paulina A. Szafrańska ◽  
Monika Wieczorek ◽  
Marek Konarzewski
Keyword(s):  
White Blood Cells ◽  
Parasitic Infections ◽  
First Year ◽  
Metabolic Rates ◽  
Overwinter Survival ◽  
Microtus Oeconomus ◽  
Root Vole ◽  
Energy Expenditures ◽  
Wbc Count ◽  
Free Ranging

Despite its presumed significance, the association between immune defence, energy expenditures and overwinter survival is rarely studied. We analysed individual variation in immunocompetence quantified as neutrophil-to-lymphocyte ratio (N/L), total white blood cells (WBC) and natural antibody levels, along with resting (RMR) and peak metabolic rates (PMR) and mortality during three consecutive winter seasons in a natural population of the root vole, Microtus oeconomus . In early winter, WBC count was negatively correlated with RMR, whereas N/L ratio was negatively correlated with swim-elicited PMR. We suggest that while the first correlation reflected the trade-off between energy allocation in immunocompetence and other metabolically demanding processes, the latter correlation stemmed from stress-induced immunosuppression elicited by the necessity to cope with swimming in frequently flooded habitat. In addition, the analysis carried out during the first year of study characterized by a high population density and prevalence of infestation with a blood parasite— Babesia spp., showed that its intensity was inversely correlated with the N/L ratio. In summary, our results suggest that elevated N/L ratio increases the winter survival of free-ranging rodents by increasing their ability to cope with parasitic infections.

scholarly journals Metabolic rates of aggressive/submissive phenotypes are colour blind in the polymorphic Gouldian finch

2021 ◽  
Author(s):  
William A. Buttemer ◽  
Vincent Careau ◽  
Mark A. Chappell ◽  
Simon C. Griffith
Keyword(s):  
Metabolic Rate ◽  
Resting Metabolic Rate ◽  
Social Rank ◽  
First Year ◽  
Metabolic Rates ◽  
Maximal Metabolic Rate ◽  
Gouldian Finch ◽  
Exercise Induced ◽  
Colour Morphs ◽  
Metabolic Indices

Evidence from a number of species suggests behaviours associated with social rank are positively correlated with metabolic rate. These studies, however, are based on metabolic measurements of isolated individuals, thereby ignoring potential effects of social interactions on metabolic rates. Here, we characterised three pertinent metabolic indices in the two predominant genetic colour morphs of the Gouldian finch (Erythrura gouldiae): diurnal resting metabolic rate (RMR), nocturnal basal metabolic rate (BMR), and exercise-induced maximal metabolic rate (MMR). Research reveals red-headed morphs consistently dominate the less aggressive black-headed morphs and the two morphs to differ in other behavioural and physiological traits. We measured daytime RMR of intermorph naïve birds (first-year virgin males maintained in total isolation from opposite colour morphs) and their metabolic responses to viewing a socially unfamiliar bird of each colour. Subsequently each bird was placed in a home cage with an opposite colour morph (intermorph exposed) and the series of measurements repeated. Daytime RMR was indistinguishable between the two morphs, whether intermorph naïve or intermorph exposed. However, both red- and black-headed birds showed a greater short-term increase in metabolic rate when viewing an unfamiliar red-headed bird than when seeing a black-headed bird, but only when intermorph naïve. Measurements of BMR and exercise-induced MMR did not differ between the two morphs, and consequently aerobic scope was indistinguishable between them. We propose that the suite of behavioural differences between these two sympatric morphs are functionally complementary and represent evolutionary stable strategies permitting establishment of dominance status in the absence of metabolic costs.

Sign in / Sign up

Export Citation Format

Share Document