Brontosaurus
"Brontosaurus" was a large, long-necked quadrupedal animal with a long, whip-like tail, and forelimbs that were slightly shorter than its hindlimbs. The largest species, "B. excelsus", weighed up to and measured up to long from head to tail. For comparison, the current largest land animal, the average male African bush elephant is 3.20 m (10.5 ft) tall at the shoulder and has a body mass of 6,000 kg (13,228 lb) or 6.6 short tons.
Ectenosaurus
Based on the size of the preserved skull, about 74 centimeters in length, "Ectenosaurus" would have reached sizes of 5,7 meters in length. It was a rare genus of mosasaur with several unique characteristics that clearly separate it from other mosasaur genera. The most prominent of these features is its elongated jaws, elongated in a similar vein to other mosasaurs with elongated jaws, such as "Plotosaurus" and "Pluridens".