NUMBER ONE HUNDRED TWENTY: The Monterey Bay Aquarium (Monterey, California, U.S.A.) just announced in 2022 they'll open the world's first large-scale deep sea animal exhibit. In honor of this fantastic news I thought I'd showcase a species that might be included in the exhibit if time travel is invented between now and 2022.
Above:
Phosphorosaurus ponpetelegans hunting bioluminescent prey at night.
- Animal: Phosphorosaurus ponpetelegans
- Name Pronunciation: Fah-sfer-us-oh-sore-us pon-pet-el-egans
- Name Meaning: "Phosphate lizard from an elegant creek"
- Named By: Takuya Konishi et al. - 2015
- Classification: Life, Eukaryota, Animalia, Chordata, Vertebrata, Gnathostomata, Osteichthyes, Sarcopterygii, Tetrapodomorpha, Tetrapoda, Reptiliomorpha, Amniota, Sauropsida, Eureptilia, Sauria, Lepidosauromorpha, Lepidosauria, Squamata, Toxicofera, Mosasauroidea, Mosasauridae, Halisaurinae
- When: ~ 72,100,000 B.C.E. (Maastrichtian stage of the Late Cretaceous epoch)
- Where: Hakobuchi Formation (Hokkaido, Japan)
- Size: 10 feet (3.048 m) long
- Diet: Carnivore
Analysis of the skull provides compelling evidence that
Phosphorosaurus ponpetelegans had well-developed binocular vision, with an estimated binocular field of view (BFoV) of 35 degrees. This value is unusually high for non-ophidian squamates that typically exhibit a BFoV of 10 to 20 degrees, and is higher than those of other measured mosasaur taxa by at least 5 degrees. Among colubrid snakes (mosasaurs were closely related to snakes), species that dwell in the dark exhibit greater BFoV than diurnal ones in both arboreal and terrestrial taxa. Known also from the Maastrichtian of Hokkaido are fossils of lantern fish (myctophids) and 10-armed cephalopods (coleoids), both of which are typically bioluminescent today. It was hence proposed that the exceptionally large, forward-facing eyes of
P.
ponpetelegans may well have been a special adaptation for a deep sea or nocturnal lifestyle, where it hunted small, bioluminescent prey while avoiding direct competition with larger, more piscine mosasaurine species such as
Mosasaurus hobetsuensis that co-existed with it. It is not hard to imagine a scenario where this species only rose to the surface at night while the larger predators were away. Studies also indicate that the animal was likely an ambush predator that would lie in wait for prey, as it was not as efficient a swimmer as larger mosasaurs, much like other halisaurines.
P.
ponpetelegans was one of two species of
Phosphorosaurus, the other being the younger (66 mya)
P. ortliebi. The generic name refers to the fact that the first species to be described,
P. ortliebi, was found in the Phosphatic chalk of the Mons Basin (Belgium). The species name,
ponpetelegans, refers the exceptional preservation of the holotype specimen of the species and the clean Pankerusano-sawa Creek where the fossil was discovered.
Above:
P. ponpetelegans skeleton replica on display at the National Museum of Nature and Science (Tokyo, Japan).
Above: HMG-1528, the holotype skull of
P. ponpetelegans.
Above:
P. ponpetelegans hunting a bioluminescent squid in the deep sea.
Above:
Mosasaurus hobetsuensis hunting an ammonite.
Above: Some of the creatures known from the Hakobuchi Formation, including
P. ponpetelegans,
Mesodermochelys undulatus (the sea turtles), and
Kamuysaurus japonicus (the hadrosaurid dinosaur carcass).
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