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.
Pliosaurus
The holotype of "P. funkei" is represented by the anterior portions of the upper and lower jaws (including premaxillary and dentary teeth), one nearly complete cervical centrum and two partial cervical centra, three pectoral centra with neural arches, fifteen dorsal centra and eight neural arches, a complete right coracoid, numerous rib fragments and gastralia, and a complete right forelimb. The referred specimen is represented by five partial cervical centra, one partial dorsal centrum, and a partial skull including the occipital condyle, a complete left quadrate, a partial left squamosal and incomplete left surangular and articular. Several fragmentary and unidentified bones also pertain to PMO 214.136. Due to the Arctic climate found on Svalbard, the sediment in which the specimens were subjected to repeated freeze-thaw cycles before collection, extensively fracturing and degrading the material. PMO 214.136 was discovered in 2007, following the collection of approximately 20,000 fragments that compose PMO 214.135 which were found moist in situ and degraded upon drying during the preparation process (individual fragments are catalogued at the University of Oslo Natural History Museum by specimen number followed by a slash and a number). Estimates of skull length are approximately for the holotype and for PMO 214.136, suggesting a total body length of for the species, making "P. funkei" one of the largest pliosaurs described so far, but this estimate has since been questioned. Due to its large size and relative completeness, the species, nicknamed "Predator X" before its formal description, gained extensive media coverage, which claimed that it was "most fearsome animal ever to swim in the oceans". Morphological and histological characters, such as the presence of a tuberosity on the humerus and a well developed anterior process on the coracoid, and abnormal hardening and increase in density of bone, indicate that both specimens were adult individuals. Even though none of the neural arches are fused to their centra in the vertebral column of both individuals (a possible juvenile trait), this feature is present in all large pliosaurids, and thus possibly paedomorphic within Pliosauridae.