Hyotissa semiplana

Hyotissa semiplana is an extinct species of large saltwater oysters, a fossil marine bivalve mollusk in the family Gryphaeidae, the foam oysters[1]

Hyotissa semiplana
Temporal range: Late Cretaceous
Fossil shells of Hyotissa semiplana from Maastrichtian age, on display at Galerie de paléontologie et d'anatomie comparée in Paris
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Bivalvia
Order: Ostreida
Family: Gryphaeidae
Genus: Hyotissa
Species:
H. semiplana
Binomial name
Hyotissa semiplana
(de Sowerby, 1825)
Synonyms
  • Pycnodonte semiplana

Description

Fossil shells of Hyotissa semiplana can reach a diameter of about 60 millimetres (2.4 in).[2] They have thick-walled valves, with rough, nodose surface.[3][4]

Distribution

Fossils of this species have been found in the Campanian-Maestrichtian of Poland, in the Santonian-Maestrichtian of Europe and North Africa and in the Campanian of South India.[3][5]

gollark: I'd just like to interject for a moment. What you’re referring to as Monad, is in fact, GNU/Monad, or as I’ve recently taken to calling it, GNU plus Monad. Monad is not an operating system unto itself, but rather another free component of a fully functioning GNU system made useful by the GNU corelibs, shell utilities and vital system components comprising a full OS as defined by POSIX. Many computer users run a modified version of the GNU system every day, without realizing it. Through a peculiar turn of events, the version of GNU which is widely used today is often called “Monad”, and many of its users are not aware that it is basically the GNU system, developed by the GNU Project. There really is a Monad, and these people are using it, but it is just a part of the system they use. Monad is the kernel: the program in the system that allocates the machine’s resources to the other programs that you run. The kernel is an essential part of an operating system, but useless by itself; it can only function in the context of a complete operating system. Monad is normally used in combination with the GNU operating system: the whole system is basically GNU with Monad added, or GNU/Monad. All the so-called “Monad” distributions are really distributions of GNU/Monad.
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gollark: Oh, not that... it should run over discord channels though.
gollark: Channel based... Discord channels?
gollark: (Was on clipboard)

References

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