Ben Creisler's Mosasaur Pronunciation Guide

Copyright Ben Creisler 2000-2012

The proper English translations of generic names and related taxon, and their preferred pronunciations.

(Moved to Oceans of Kansas, July 5, 2012)

Go to the guide


Each entry begins with the name of the genus in italics--bold face indicates a valid name for a generally recognized taxon; light face indicates that the name is preoccupied, or is considered a nomen dubium or a junior synonym of another name. The name is followed by the author or authors of the name, the year of official publication, and an interpreted meaning of the name in quotes. On a separate line are the phonetic pronunciation (see comments below under "Pronunciation"), the etymology (see comments below under "Etymology"), an asterisk when the etymology was provided by the author of the name, and the Latin gender of the name: (m) = masculine, (f) = feminine, (n) = neuter. The text gives a fuller explanation of the name and a short description of the animal. When available, the number of vertebrae, the length of the entire body and of the skull are listed. The type species and any additional species that are commonly recognized by modern researchers are briefly listed and discussed. Finally, the entry provides a classification at the level of subfamily, the time period during which the animal lived, and the continent on which its fossils have been found (NA. "North America," SA. "South America," Eur. "Europe," Ant. "Antarctica," Afr. "Africa," Aus. "Australia"). Senior synonyms or replacement names appear in brackets with an equal sign. The term [nomen dubium] is used to indicate a name that is based on material generally considered inadequate to permit a useful scientific diagnosis of the proposed taxon.

Subfamily Names:

Bold face indicates subfamilies that most researchers accept. A brief diagnosis of the group follows, with a list of recognized members, and "undescribed members" for new discoveries that have not been described yet in the official scientific literature.


For purposes of this guide, the following consonants and consonant combinations have the regular sound assigned in English spelling:

b, ch, d, f, h, j, k, l, m, n, p, r, sh, t, th, v, w, y, z.

Special rules:

g by itself always stands for the hard sound in "get";
ng is like in "sing";
s is always unvoiced as in "sit" or "miss";
zh stands for the sound z has before "u" in "azure" (that is, a voiced sh sound);
y is a semi-consonant as in "yell," not a vowel as in "why."

The letters used to indicate short and long vowels, and diphthongs, have the sounds indicated in the following word examples:

a (cat), ah (father), ay (bay), aw (law); e (bet), ee (beet); i (it), ie (lie); o (got), oh (toe), oy (boy); u (put), uh (cut), oo (boot), ow (cow).

Names created in the 19th century are generally given the traditional Latin accent (based on the length of the next-to-last syllable); names created more recently are usually stressed on word-roots regardless of where Latin rules would assign the accent. Upper case letters indicate a stressed syllable, bold face indicates the main stress. When pronunciations with different stresses are possible, alternate versions may be given.

Maori Words in Mosasaur Names:

Words from the Maori language occur in a number of generic and specific names for mosasaurs found in New Zealand. The pronunciation given for names such as Taniwhasaurus is based on English approximations for the original Maori sounds as recommended in various Maori-English dictionaries. Distinctions between long and short vowels are particularly important in Maori, but may have no exact English equivalent. The following written vowels have special sounds when approximating Maori values: short a is more like "uh"; o is like "aw" (never "oh"); u is like "oo" (short or long as in English "look" or "boot"); wh is like "f" and ng has the sound in "singing" (no hard "g" sound). Thus Maori "Taniwha" would be pronounced TUHN-i-fuh in Taniwhasaurus.

Species Names:

Latin species names ending in the genitive form "i" or "ae" that are derived from modern personal names generally keep the stress accent of the original name.


Most names are derived from Greek (Gr.) or Latin (Lat.) roots. Bold face vowels indicates long vowels or diphthongs in Greek or Latin. The general meaning of word roots is given in quotes. Other languages used to form names include Chinese (Chin.), Spanish (Span.), English (Eng.), and Maori.


Researchers divide the vertebral columns of mosasaurs into distinct regions, though sometimes using different terms. The exact number of vertebrae probably varied somewhat among individuals. Mosasaurs have 7 cervical (neck) vertebrae, including the atlas-axis complex (vertebrae 1 and 2) that articulates with the base of the skull. The dorsal vertebrae come between the cervicals and the "sacral" vertebra, and can be divided into anterior (thoracic) dorsals with long ribs, and posterior (lumbar) dorsals with short ribs. Mosasaurs do not have a "sacrum" as such--the ilium has no direct contact with the vertebral column and there is no group of "sacral" vertebrae fused together as in many other reptiles. Russell (1967) counted the first pygal as the single "sacral" vertebra since it is "almost indistinguishable from the anteriormost caudal" and the "transverse process of the first pygal vertebra is more than twice as long as the synapophysis of the last dorsal." In life, the ilia were probably attached to the transverse processes of the first pygal by ligaments of some kind. According to Russell (1967), the tail vertebrae can be divided into three regions: pygals ("a basal region where vertebrae lack haemal arches); intermediate region ("where they possess haemal arches"); and terminal region ("where transverse arches are absent").


Mosasaurs are members of the Squamata, the group of diapsid reptiles that includes living lizards and snakes. Mosasaurs are known only from the Late Cretaceous (Turonian-Maastrichtian) and are classified in a single family called the Mosasauridae. The Mosasauridae as currently defined includes a number of subfamilies divided into tribes, plus some unusual forms that may belong in new subfamilies of their own. The Mosasauridae in turn are placed in the superfamily Mosasauroidea, which also includes the aigialosaurs--a group of extinct elongated, semi-aquatic squamates (Aigialosaurus "seashore lizard," Opetiosaurus "awl (tooth) lizard," Carsosaurus "Carso (Mountains) lizard"; Trieste aigialosaur; Texas aigialosaur) known from the early Late Cretaceous (Cenomanian-Turonian). The limbs of aigialosaurs are much less modified than the limbs of mosasaurs and provide a model for the transition from terrestrial legs to swimming paddles. Polcyn, Tchernov and Jacobs (1999) have described another primitive member of the Mosasauroidea under the preoccupied name Haasia (for Georg Haas)--the new taxon appears to be distinct from "aigialosaurs" and dates from the Early Cenomanian of Israel. Other possible relatives of the mosasaurs outside the Mosasauroidea proper include the dolichosaurs ("long lizards") and Coniasaurus ("Cretaceous lizard")--small elongated aquatic squamates that are still incompletely known. All of these extinct lizard-like animals (mosasaurids, aigialosaurs, "Haasia," dolichosaurs, Coniasaurus) have features that indicate a close relationship to the varanoid (monitor) lizards that still survive today.

While most paleontologists have accepted the varanoid-mosasaur connection originally proposed by Cuvier, Edward Drinker Cope saw mosasaurs as more closely related to snakes and erected a special suborder he called the Pythonomorpha. Recently, a few modern researchers have revived the mosasaur-snake connection (Lee 1997; Caldwell & Lee 1997), based in part on studies of snake-like marine reptiles such as Pachyrhachis ("thick spine"). Their conclusions remain controversial and have been challenged in a recent paper (Zaher & Rieppel 1999), based on the apparent different way the teeth are embedded in the jaw in snakes and mosasaurs.

On-going work is likely to revise current classifications of mosasaurs in major ways. (Note, however, that the name guide provided here sticks to a more traditional classification.) Gorden Bell's 1997 cladistic analysis shifted Prognathodon and Plesiotylosaurus from the Plioplatecarpinae to the Mosasaurinae, and indicated that the well-established genera Mosasaurus, Clidastes, Prognathodon and Platecarpus are paraphyletic (that is, each genus as commonly defined contains species representing some, but not all, descendants of a common ancestor). Important new taxa to be formally described soon include "Russellosaurus" (a form related to tylosaurs and plioplatecarpines) and "Oronosaurus" (a giant prognathodont from Israel). New species or even new genera likely exist among the surprising wealth of mosasaur specimens recently unearthed in Antarctica, as well as among new remains found in South America and Japan. Other potential "hot spots" for new mosasaurs include Africa and Russia, while important studies of mosasaurs from New Zealand continue. North America is likely to remain the mosasaur "capital" of the world, though, and continues to supply the most complete and best preserved specimens--recent finds include skeletons associated with large patches of fossil scales, embryos, and stomach contents. Re-descriptions of well-known specimens (such as the "Mosasaurus conodon" from South Dakota) are also underway, and may result in creation of new taxa.

Collection and Museum Abbreviations:

Academy of Natural Sciences Philadelphia, PA;
British Museum of Natural History (London);
Brigham Young University, UT;
California Institute of Technology;
Carnegie Museum, Pittsburgh, PA;
Denver Museum of Natural History, Denver, CO;
Sternberg Museum of Natural History, Hays, Kansas;
Field Museum of Natural History (Chicago);
Geological Survey of Alabama;
Institute Royal des Sciences Naturelles de Belgique;
Kansas University, Vertebrate Paleontology, Natural History Museum. Lawrence, Kansas;
Kansas University Museum of Natural History;
Museum of Comparative Zoology (Harvard University);
Natuurhistorisch Museum Maastricht, The Netherlands;
New Zealand Geological Survey;
South Dakota School of Mines and Technology, Rapid City, SD;
Southern Methodist University, Shuler Museum of Paleontology;
University of California Museum of Paleontology (Berkeley, CA);
United States National Museum (Washington, D.C.);
Yale Peabody Museum (New Haven, CT)


A number of professional researchers have been very helpful in answering my questions and supplying important information on the topic of mosasaurs. I would especially like to thank Donald Baird, Gorden Bell, Theagarten Lingham-Soliar and Ken Carpenter. Tracy Ford has been invaluable in helping supply photocopies of original articles. Any errors, misunderstandings, outdated information or oversights in this guide are my own, however. Corrections and suggestions for improvements would be greatly appreciated.


A good selection of references for mosasaur articles can be found on the Oceans of Kansas website. Some additional recent references include:

  1. Holmes, R., M. Caldwell & S. Cumbaa. 1999. A new specimen of Plioplatecarpus (Mosasauridae) from the lower Maastrichtian of Alberta; comments on allometry, functional morphology, and paleoecology. Canadian Journal of Earth Sciences. 36(3):363-369.
  2. Kuypers, M., J. Jagt, H. Peeters & D. De Graaf, 1998. Late Cretaceous mosasaurs from Liege-Limburg: New finds lead to new insights. Publicaties van het Natuurhistorisch Genootschap in Limburg. 41 (1):5-48.
  3. Polcyn, M., E. Tchernov & L. Jacobs. 1999. The Cretaceous biogeography of the eastern Mediterranean with a description of a new basal mosasauroid from 'Ein Yabrud, Israel: in Tomida, Rich & Vickers-Rich, eds. 1999. Proceedings of the Second Gondwanan Dinosaur Symposium. National Science Museum Monographs No. 15. Tokyo, Japan.
  4. Zaher, H. & O. Rieppel, 1999. Tooth implantation and replacement in squamates, with special reference to Mosasaur lizards and snakes. American Museum of Natural History Novitates. 3271: 1-19.

Go to the guide