Definition: The number of fossil occurrences in the Paleobiology Database (https://paleobiodb.org) that are identified as belonging to a particular taxon or any of its subtaxa.
Definition: 1) Producing live offspring from within the body of the parent (Lincoln et al., 1998). 2) Development of an embryo within the body of the parent, in part, resources passing directly from parent to embryo (Barnes et al., 2006).
Attribution: Lincoln, R., Boxshall, G. & Clark, P., 1998. A dictionary of ecology, evolution and systematics (2nd ed.). Cambridge: Cambridge University of Press. Barnes R.S.K., Calow P., Olive P.J.W., Golding, D.W, and Spicer, J.I. 2006. The invertebrates: a new synthesis, Oxford: Blackwell Science Ltd.
http://www.marinespecies.org/traits/wiki/Traits:Viviparous
