Why Were Dinosaurs So Big?

Why were dinosaurs so big?: originally appeared on Quora: The best answer to any question. Ask a question, get a great answer. Learn from experts and access insider knowledge. You can follow Quora on Twitter, Facebook, and Google+. Answer by Marc Srour, Invertebrate Paleontologist Image by MathKnight There is actually no uncontroversial explanation for the as-of-yet unparalleled size of dinosaurs. If you look at the distribution of large sizes in dinosaurs, one distinction becomes clear: the only dinos that were small (less than 1m) were carnivorous theropods. Except for the 70 cm Fruitadens Haagarorum, no herbivorous ornithischians were small. The evolution of teeth in ornithischian lineages proceeded along very similar lines independently, and each innovation was accompanied by a bump in body size. Teeth are merely the most fossilisable sections of the digestive system. If they changed, then the rest of the animals' physiology was also changing in such a way as to enable larger body sizes, from getting larger guts to becoming quadrupedal (the first ornithischians were small and bipedal). In turn, this leads to changing ecological opportunities, feeding on different plants, being able to eat much more at once, and thus beginning the cycle of ever-growing sizes. This would then enter into a coevolutionary back-and-forth with their theropodan predators, eventually resulting in the sauropods, tyrannosaurids, and the other giants. What were the ornithischians eating to suppor...
Source: Science - The Huffington Post - Category: Science Source Type: news

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Publication date: Available online 10 December 2018Source: Molecular and Cellular EndocrinologyAuthor(s): Christoph Schmid, Claudia Ghirlanda, Cornelia Zwimpfer, Oliver Tschopp, Richard A. Zuellig, Markus NiessenAbstractCystatin C (CysC) is a marker for estimation of glomerular filtration rate (GFR). CysC levels may depend not only on clearance/GFR but possibly also on changes in production. Our studies on tissue distribution of CysC protein in mice showed that adipose tissue expresses significant amounts of CysC, suggesting that adipocytes could contribute to circulating CysC levels in vivo. As growth hormone (GH) and tri...
Source: Molecular and Cellular Endocrinology - Category: Endocrinology Source Type: research
Conclusions: Old age and radiographic predictors indicating large tongue size (large TA, long alveolar line of the mandible to the hyoid bone and mandible to the hyoid bone) were associated with an increased rate of difficult laryngoscopy in acromegaly patients. Preoperative radiographic measurements of tongue size can be helpful for safe airway management in such patients.
Source: Journal of Neurosurgical Anesthesiology - Category: Anesthesiology Tags: Clinical Investigations Source Type: research
ConclusionOctreotide SC depot provided higher exposure (AUC) than octreotide IM, maintained biochemical control in patients with acromegaly and symptom control in patients with functioning NETs, and was well tolerated with a safety profile consistent with octreotide IM.ClinicalTrials.gov identifierNCT02299089.
Source: Cancer Chemotherapy and Pharmacology - Category: Cancer & Oncology Source Type: research
ConclusionsIn patients with newly diagnosed acromegaly, HT frequency was significantly increased and it was independently associated with the RRI value. Therefore, these patients should be closely monitored for HT —the most frequent and important cardiovascular risk factor—and treated before they develop target organ damage.
Source: High Blood Pressure and Cardiovascular Prevention - Category: Cardiology Source Type: research
Authors: Boguszewski CL, Boguszewski MCDS Abstract Several components of the GH axis are involved in tumor progression and GH-induced intracellular signaling has been strongly associated with breast cancer susceptibility in genome-wide association studies. In the general population, high IGF-I levels and low IGFBP-3 levels within the normal range are associated with the development of common malignancies, and components of the GH-IGF signaling system exhibit correlations with clinical, histopathological and therapeutic parameters in cancer patients. Despite promising findings in preclinical studies, anti-cancer the...
Source: Endocrine Reviews - Category: Endocrinology Tags: Endocr Rev Source Type: research
Authors: García-Alvarez M, Climent V Abstract Acromegaly is a rare disease characterized by high levels of growth hormone (GH) and insulin- like growth factor 1 (IGF-1). The excess of GH leads to the development of different manifestations in different organs, from subtle signs in the bones and soft tissues to the development of respiratory and cardiac insufficiency. In the cardiovascular system, the GH/IGF-1 axis exerts its influence on three major aspects: myocyte growth and structure, cardiac contractility and vascular function. In this article, we review the different cardiovascular and respiratory compl...
Source: Minerva Endocrinologica - Category: Endocrinology Tags: Minerva Endocrinol Source Type: research
Xiaopeng Guo, Tian Meng, Jiuzuo Huang, Xiaojun Wang, Wei Lian, Kan Deng, Lu Gao, Zihao Wang, Bing Xing, Xiao Long
Source: Frontiers in Endocrinology - Category: Endocrinology Source Type: research
Purpose of review Elevated circulating levels of growth hormone (GH) and/or increased expression of the GH receptor in the kidney are associated with the development of nephropathy in type1 diabetes and acromegaly. Conditions of GH excess are characterized by hyperfiltration, glomerular hypertrophy, glomerulosclerosis and albuminuria, whereas states of decreased GH secretion or action are protected against glomerulopathy. The direct role of GH's action on glomerular cells, particularly podocytes, has been the focus of recent studies. In this review, the emerging role of GH on the biological function of podocytes and its ...
Source: Current Opinion in Nephrology and Hypertension - Category: Urology & Nephrology Tags: HORMONES, AUTACOIDS, NEUROTRANSMITTERS AND GROWTH FACTORS: Edited by Mark Cooper and Merlin Thomas Source Type: research
ConclusionsIn acromegaly,GSTP1 gene methylation associates with resistance to SSA treatment, especially in patients carrying also theAHR rs2066853 variant, and with increased prevalence of colonic polyps and diabetes mellitus.
Source: Journal of Endocrinological Investigation - Category: Endocrinology Source Type: research
ConclusionsThe analysis of preclinical studies carried out in somatotroph and corticoph adenomas points out that pasireotide shows a cell-specific activity, exerting its biological effects via different SSTs in the different adenoma histotypes.
Source: Pituitary - Category: Endocrinology Source Type: research
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