Melt chocolate chips and shortening in top of double boiler over hot, not boiling,
water; remove from heat. Cool mixture to 85 degrees F, stirring constantly.
Meanwhile, cut marshmallows in half horizontally; flatten with rolling pin. Set
On wax paper-covered tray, form head and hind feet of turtle by arranging three
pecan halves with ends touching in center; for front feet, place one pecan quarter
on each side of head. Arrange 24 of these clusters as bases for turtles. Spoon 1/2
teaspoon melted chocolate mixture into center of each cluster of pecans.
To make turtle shell, place flattened marshmallow half in center of pecans on
top of chocolate; press lightly to adhere. Spoon a small amount of chocolate onto
marshmallow and spread with a spatula to cover top and edges of marshmallow.