Growth in Reptiles

Avery, R.

doi:10.1159/000213587

Cited by 37 publications

(26 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The study however indicates that this outstanding cartilaginous regeneration appears related to the permanence of proliferating cells in the growing centers of the articular cartilage and of the metaphyseal cartilage (growth plate) during most of the lifetime in these reptiles that present a more or less continuous growth [3]. The present study made use of adult lizards, estimated by the size in this species above 12 cm for both sexes although it was unknown whether they were young or old adults.…”

Section: Articular Cartilage Regeneration In Terrestrial Vertebratesmentioning

confidence: 85%

“…However, the extension and frequencies of these stem cell niches are likely variable among the adult forms of different species of vertebrates, and in particular between permanently growing species of heterothermic anamniotes such as fish and amphibians, or heterothermic amniotes such as extant reptiles, in comparison to those present in homeothermic amniotes such as birds and mammals where the process of growth ceases with sexual maturity. As far as is known, most turtles, crocodilians, lizards and snakes grow during most of their lifespan, albeit at different rates, and, although their growth slows down especially after reaching sexual maturity and in the later stages of life, it likely never stops completely [3].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Regeneration of the Epiphysis Including the Articular Cartilage in the Injured Knees of the Lizard Podarcis muralis

Alibardi

2015

JDB

View full text Add to dashboard Cite

Cartilage regeneration is massive during tail regeneration in lizards but little is known about cartilage regeneration in other body regions of the skeleton. The recovery capability of injured epiphyses of femur and tibia of lizard knees has been studied by histology and 5BrdU immunohistochemistry in lizards kept at high environmental temperatures. Lizard epiphyses contain a secondary ossified center of variable extension surrounded peripherally by an articular cartilage and basally by columns of chondrocytes that form the mataphyseal or growth plate. After injury of the knee epiphyses, a broad degeneration of the articular cartilage during the first days post-injury is present. However a rapid regeneration of cartilaginous tissue is observed from 7 to 14 days post-injury and by 21 days post-lesions, a large part of the epiphyses are reformed by new cartilage. Labeling with 5BrdU indicates that the proliferating cells are derived from both the surface of the articular cartilage and from the metaphyseal plate, two chondrogenic regions that appear proliferating also in normal, uninjured knees. Chondroblasts proliferate by interstitial multiplication forming isogenous groups with only a scant extracellular matrix that later increases. The high regenerative power of lizard articular cartilage appears related to the permanence of growing cartilaginous centers in the epiphyses of long bones such as those of the knee during adulthood. It is likely that these regions contain resident stem cells that give rise to new chondroblasts of the articular and metaphyseal cartilage during most of the lizard's lifetime, but can produce an excess of cartilaginous tissues when stimulated by the lesion. OPEN ACCESSJ. Dev. Biol. 2015, 3 72

show abstract

Section: Articular Cartilage Regeneration In Terrestrial Vertebratesmentioning

confidence: 85%

Section: Introductionmentioning

confidence: 99%

Regeneration of the Epiphysis Including the Articular Cartilage in the Injured Knees of the Lizard Podarcis muralis

Alibardi

2015

JDB

View full text Add to dashboard Cite

show abstract

“…This inherent underestimation of T b in indeterminate growers by the MGR-T b -equation is important in extant non-avian reptiles, but could also be significant in several dinosaurs presumed to reproduce well before reaching full size M A [35,36,69]. In non-avian reptiles, growth can also be highly variable, reflecting environmental inconsistencies within and between years in general [70] and in ambient temperatures in particular [70,71]. For example, the most northerly distributed extant crocodilian species, the American Alligator, stops eating when ambient temperature drops below 16 °C.…”

Section: Discussionmentioning

confidence: 99%

“…It is only during the warmer months of the year during active feeding that growth occurs [71]. During winter torpor (hibernation), growth in non-avian reptiles stops completely [70]. Since MGR of larger reptiles and dinosaurs (annual growth marks are preserved in long bones; for a review on the establishment of growth trajectories, see 35,36) is calculated at a yearly basis, phases of growth and not growth within the year are averaged.…”

Section: Discussionmentioning

confidence: 99%

“…According to the biophysical model of Seebacher [3], larger ectothermic animals have more stable body temperatures than smaller. However, reasons for the natural variability seen in growth rates of extant similar-sized individuals are not only ambient temperature and thermoregulation but also food availability, quality and intake, and water availability [70]. Moreover, the sample size of studied extant non-avian reptiles is much larger than that of Dinosauria.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Body Temperatures in Dinosaurs: What Can Growth Curves Tell Us?

Griebeler

2013

PLoS ONE

View full text Add to dashboard Cite

To estimate the body temperature (BT) of seven dinosaurs Gillooly, Alleen, and Charnov (2006) used an equation that predicts BT from the body mass and maximum growth rate (MGR) with the latter preserved in ontogenetic growth trajectories (BT-equation). The results of these authors evidence inertial homeothermy in Dinosauria and suggest that, due to overheating, the maximum body size in Dinosauria was ultimately limited by BT. In this paper, I revisit this hypothesis of Gillooly, Alleen, and Charnov (2006). I first studied whether BTs derived from the BT-equation of today’s crocodiles, birds and mammals are consistent with core temperatures of animals. Second, I applied the BT-equation to a larger number of dinosaurs than Gillooly, Alleen, and Charnov (2006) did. In particular, I estimated BT of Archaeopteryx (from two MGRs), ornithischians (two), theropods (three), prosauropods (three), and sauropods (nine). For extant species, the BT value estimated from the BT-equation was a poor estimate of an animal’s core temperature. For birds, BT was always strongly overestimated and for crocodiles underestimated; for mammals the accuracy of BT was moderate. I argue that taxon-specific differences in the scaling of MGR (intercept and exponent of the regression line, log-log-transformed) and in the parameterization of the Arrhenius model both used in the BT-equation as well as ecological and evolutionary adaptations of species cause these inaccuracies. Irrespective of the found inaccuracy of BTs estimated from the BT-equation and contrary to the results of Gillooly, Alleen, and Charnov (2006) I found no increase in BT with increasing body mass across all dinosaurs (Sauropodomorpha, Sauropoda) studied. This observation questions that, due to overheating, the maximum size in Dinosauria was ultimately limited by BT. However, the general high inaccuracy of dinosaurian BTs derived from the BT-equation makes a reliable test of whether body size in dinosaurs was ultimately limited by overheating impossible.

show abstract

Diminishing returns limit energetic costs of climate change

Levy

Borchert

Rusch

et al. 2017

Ecology

View full text Add to dashboard Cite

Changes in the time available for organisms to maintain physiologically preferred temperatures (thermal opportunity) is a primary mechanism by which climate change impacts the fitness and population dynamics of organisms. Yet, it is unclear whether losses or gains in thermal opportunity result in proportional changes in rates of energy procurement and use. We experimentally quantified lizard food consumption and energy assimilation at different durations of thermal opportunity. We incorporated these data in an individual-based model of foraging and digestion in lizards to explore the implications of nonlinear responses to shifts in thermal opportunity across a wide geographic range. Our model predicts that shifts in thermal opportunities resulting from climate change alter energy intake primarily through digestion rather than feeding, because simulated lizards were able to fill their gut faster than they can digest their food. Moreover, since rates of energy assimilation decelerate with increasing thermal opportunity, shifts in daily energetic assimilation would depend on the previous opportunity for thermoregulation. In particular, the same changes in thermal opportunity will have little impact on lizards from warm locations, while having a large impact on lizards from cold locations where thermoregulation is possible for only a few hours each day. Energy expenditure followed spatial patterns in thermal opportunity, with greater annual energy expenditure occurring at warmer locations. Our model predicts that lizards will spend more energy under climate change by maintaining higher body temperatures and remaining active longer. However, the predicted changes in energy assimilation following climate change greatly exceeded the predicted increases in energy expenditure. Simple models, which assume constant rates of energy gain during activity, will potentially mislead efforts to understand and predict the biological impacts of climate change.

show abstract

Growth in Reptiles

Cited by 37 publications

References 30 publications

Regeneration of the Epiphysis Including the Articular Cartilage in the Injured Knees of the Lizard Podarcis muralis

Regeneration of the Epiphysis Including the Articular Cartilage in the Injured Knees of the Lizard Podarcis muralis

Body Temperatures in Dinosaurs: What Can Growth Curves Tell Us?

Diminishing returns limit energetic costs of climate change

Contact Info

Product

Resources

About