[{"clade":"Total group Astroscopus","fossil":"Astroscopus countermani","left":"Astroscopus_y_graecum","right":"Uranoscopus_sulphureus","min":"7.246","max":"38.13793393","locality":"St. Mary's Formation, USA","authority":"Carnevale et al. (2011)","age_authority":"Tortonian, age estimate derived from Gradstein et al. (2012)"}]