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.
Spinosaurus
"Spinosaurus" was among the largest of all known carnivorous dinosaurs, nearly as large as or even larger than "Tyrannosaurus", "Giganotosaurus" and "Carcharodontosaurus". Estimates published in 2005, 2007, and 2008 suggested that it was between in length and in weight. New estimates published in 2014 and 2018 based on a more complete specimen, supported the earlier research, finding that "Spinosaurus" could reach lengths of . The latest estimates suggest a weight of . The skull of "Spinosaurus" was long and narrow, similar to that of a modern crocodilian. "Spinosaurus" is known to have eaten fish, and most scientists believe that it hunted both terrestrial and aquatic prey; evidence suggests that it lived both on land and in water as a modern crocodilian does. The distinctive spines of "Spinosaurus", which were long extensions of the vertebrae, grew to at least long and were likely to have had skin connecting them, forming a sail-like structure, although some authors have suggested that the spines were covered in fat and formed a hump. Multiple functions have been put forward for this structure, including thermoregulation and display.