In a recent article, Hayes et al. (2006) assessed the effects of nine pesticides individually (at 0.10 ppb) and in combination (each at 0.10 ppb) on time to foreleg emergence and time to complete tail resorption in Rana pipiens.
Yet, according to LeBlanc and Wang, we simply assessed the effects of nine pesticides individually (at 0.10 ppb) and in combination (each at 0.10 ppb) on time to foreleg emergence and time to complete tail resorption.
We assessed effects on 10 parameters: time to foreleg emergence (FLE) and time to complete tail resorption (TR), snout-vent length (SVL) and body weight (BW) at metamorphosis, mortality, gonadal development, thymus histology, disease rates, and the interaction between time to TR and SVL and BW at metamorphosis.
PJS, JSB, KF and MDF conceived and designed the murine experiments; PJS analyzed the mouse data and wrote the manuscript; TR completed the tail injections; and JSB, KF and MDF designed research and wrote the manuscript.
These fossils one might expect would have pretty much every bone preserved, but a good hunt down of the available specimens soon revealed that even those blessed with feathers and the like very rarely had a totally complete tail.
I widened my search and began digging into other museum collections, reading descriptions of fossils in scientific papers, checking out photos of dinosaur specimens and asking colleagues and simply trying to track down every dinosaur fossil I could that had a complete tail.
It was not until 1927 that a largely complete tail of Dimetrodon was described.
Although no complete individuals were found, some material was discovered in association, including a nearly complete tail, hip, several dorsal vertebrae and some limb elements of one individual.
However, this often takes many days after natural metamorphosis has started, and to expose tadpoles to high levels of exogenous T3 for long periods of time to induce complete tail regression is impractical, as it is most often lethal.
