Morphogenesis of placental membranes in the viviparous, placentotrophic lizard Chalcides chalcides (Squamata: Scincidae)

@article{Blackburn1997MorphogenesisOP,
  title={Morphogenesis of placental membranes in the viviparous, placentotrophic lizard Chalcides chalcides (Squamata: Scincidae)},
  author={Daniel G. Blackburn and Ian P. Callard},
  journal={Journal of Morphology},
  year={1997},
  volume={232}
}
In the scincid lizard Chalcides chalcides, females ovulate small ova and supply most of the nutrients for development by placental means. The yolk is enveloped precocially by extraembryonic ectoderm and endoderm during the gastrula stage, establishing a simple bilaminar yolk sac placenta. The shell membrane begins to degenerate at this time, resulting in apposition of extraembryonic and maternal tissues. A true chorioplacenta has developed by the early pharyngula stage, as has a choriovitelline… 
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References

SHOWING 1-10 OF 27 REFERENCES
Histology of the late‐stage placentae in the matrotrophic skink Chalcides chalcides (Lacertilia; Scincidae)
TLDR
Morphologically, the mature placentae of C. chalcides are among the most specialized to have been described in reptiles, reflecting the substantial maternal‐fetal nutrient transfer that occurs in this species.
Evolution of reptilian placentation: Development of extraembryonic membranes of the Australian scincid lizards, Bassiana duperreyi (Oviparous) and Pseudemoia entrecasteauxii (Viviparous)
TLDR
A revision of a classic model for the evolution of placentation among Reptilia, which predicts specific relationships among reproductive characteristics and thus is testable by comparative analysis among other species within the Eugongylus group of Australian skinks.
Morphology of the reproductive tract in a lizard exhibiting incipient viviparity (Sphenomorphus fragilis) and its implications for the evolution of the reptilian placenta
TLDR
The findings suggest that the reduction in shell thickness associated with the evolution of a placenta is due to a decrease in the number of shell glands in the uterus and is not a delay or inhibition of the shelling process per se.
Placentation in the lizard Gerrhonotus coeruleus with a comparison to the extraembryonic membranes of the oviparous Gerrhonotus multicarinatus (Sauria, Anguidae)
Paraffin sections of an ontogenetic series of embryos of the viviparous lizard Gerrhonotus coeruleus and the oviparous congener G. multicarinatus reveal that although general features of the
Placental structure of the Australian lizard, Niveoscincus metallicus (Squamata: Scincidae)
TLDR
A unique type of reptilian allantoplacenta was described by Weekes [1930] from a single embryonic stage of the Tasmanian skink, Niveoscincus ocellatus (as Lygosoma (Liolepisma) ocellatum) and assigned N. metallicus to this placental category but did not provide a description.
Chorioallantoic placentation in squamate reptiles: Structure, function, development, and evolution
TLDR
Phylogenetic analyses suggest that placental organs have originated on more than 100 occasions among squamate reptiles, and indicate that three separate lineages have converged on substantial placentotrophy through the evolution of specialized histotrophic placentae.
Development of the extraembryonic membranes and histology of the placentae in Virginia striatula (Squamata: Serpentes)
Development of the extraembryonic membranes and their structural alignment in the formation of the four placental categories that occur in Virginia striatula is similar to that of other Serpentes.
Yolk sac placentation in reptiles: Structural innovation in a fundamental vertebrate fetal nutritional system
TLDR
The yolk sac of viviparous reptiles contributes to three categories of placentation, the choriovitelline placenta, which also occurs in marsupial and eutherian mammals, and the Omphaloplacenta and omphalallantoic placentA, which occur only among squamate reptiles (lizards and snakes).
A review of placentation among reptiles with particular regard to the function and evolution of the placenta
TLDR
It is suggested that in reptiles with and obvious reduction in the yolk-content of their eggs at the time of ovulation, and its invaribale accompaniment by a speciallized folded glandular area of allanto-placentation, theYolk-sac placenta would gradually lose significance as a water absorbing organ, but the most primitive expression of viviparity among repitles.
Placental Structure and Nutritional Provision to Embryos in Predominantly Lecithotrophic Viviparous Reptiles
TLDR
Embryonic nutrition in these predominantly lecithotrophic species is characterized by features shared with oviparous ancestors combined with supplemental advantages to uterine gestation.
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