Furthermore , they were equipped with double - rooted canines , a lower premolar with a reduced or absent metaconid and a more elongated lower premolar than their predecessors .
With the exception of Prokennalestes , these advanced forms lacked a Meckelian groove .
They were equipped with double - rooted canines , a lower premolar with a reduced or absent metaconid and a more elongated lower premolar than their predecessors .
With the exception of Prokennalestes , these advanced forms lacked a Meckelian groove .