ASU's International Institute for Species Exploration unveiled the 'top 10' new species out of 18,516 discovered in 2007, as part of the State of Observed Species report issued yesterday.
One is a Devonian fish fossil [right] which is the oldest known vertebrate found to give live birth. From the ASU SOS report site:
Name: Materpiscis attenboroughi
Common Name: Mother Fish
How it made the Top 10: This new species is the oldest known vertebrate to be viviparous (live bearing). The fossilized specimen is an extremely rare find, showing a mother fish giving birth approximately 380 million years ago. The holotype specimen has been nicknamed "Josie" in honor of John Long's mother, who recently passed away.
Reference: Long, J.A., K. Trinajstic, G.C. Young & T. Senden. 2008. Live birth in the Devonian period. Nature 453(7195): 650–652.