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Evolution of placentation among squamate reptiles: recent research and future directions.
Squamate reptiles are uniquely suited to study of evolution of reproductive mode and pattern of embryonic nutrition. Viviparous species have evolved from oviparous ancestors on numerous occasions,Expand
Yolk sac placentation in reptiles: Structural innovation in a fundamental vertebrate fetal nutritional system
The extraembryonic membranes of amniote vertebrates are shared structures that have a brief, yet substantive role in the ontogeny of the organism. The yolk sac, which is the first of these structuresExpand
This section gives an elaborate interface between the developing embryo and its immediate environment. It shows how the structures compartmentalize the egg by enclosing specific egg and embryonicExpand
Comparison of nutrient transport across the placenta of lizards differing in placental complexity.
We have reviewed published and new quantitative data on the net uptake of nutrients by embryos of oviparous and viviparous lizards that vary in chorioallantoic placental complexity to betterExpand
Placental nutrition in a viviparous lizard (Pseudemoia pagenstecheri) with a complex placenta
The composition of egg yolks and neonates of the viviparous lizard, Pseudemoia pagenstecheri, one of the most placentotrophic reptiles studied to date, are described. Neonates (43.3 ± 5.2 mg) haveExpand
Placental transfer of nutrients during gestation in the viviparous lizard, Pseudemoia spenceri
Abstract Energy, ionic, protein and lipid contents and fatty acid profiles for the major lipid classes of freshly ovulated eggs and neonates of the viviparous lizard, Pseudemoia spenceri, wereExpand
Embryonic metabolism and growth in lizards of the genus Eumeces
Abstract Eggs of Eumeces fasciatus are 398 ± 25 mg and of E. anthracinus are 293 ± 27 mg. At 27°C, incubation in E. fasciatus is 24.8 ± 0.7 days and E. anthracinus is 26.9 ± 0.4 days, shorter thanExpand
Calcium provision to oviparous and viviparous embryos of the reproductively bimodal lizard Lacerta (Zootoca) vivipara
SUMMARY Embryos of oviparous squamate reptiles typically obtain calcium from both yolk and eggshell but differ from other oviparous amniotes (turtles, birds and crocodilians) because they are heavilyExpand
Development of the uterine shell glands during the preovulatory and early gestation periods in oviparous and viviparous Lacerta vivipara
The evolutionary process leading to the emergence of viviparity in Squamata consists of lengthening the period of egg retention in utero coupled with marked reduction in the thickness of theExpand