Can you please clarify the idea of Safna Mar'ah? The Soncino translates as Parthenogenesis, but is that really so? Is the Gemarah really saying a chicken can get impregnated by the dust?
Is there any later explanations in the Rishonim or Achronim?
Parthenogenesis refers to an egg that develops into a child without being impregnated by a male's sperm. I don't believe that's what the Gemara is referring to here. Safna Me'ara *does* mean that the chicken's egg was not impregnated, but that egg will never develop into a chicken.
In our Sugya, RASHI DH Bidsafna explains that Safna Me'ara means thata hen is "warmed from the ground and gives birth [Yoledes]." However, he does not mean that she gives birth to a *chicken*. She gives birth to an *egg*, as is clear from the usage of the term "Yoledes" in Beitzah 7a (bottom of the Daf), with respect to Safna Me'ara.