See text Meristodonoides is an extinct genus of hybodont known from the mid-late Cretaceous, with potential records dating back to the Jurassic.

[2] The genus is primarily known from remains from the Cretaceous of North America and Europe, spanning from the Aptian/Albian to Maastrichtian, making it one of the last surviving hybodont genera, though records of the genus likely extend as far back as the Late Jurassic, based on an undescribed skeleton from the Tithonian of England, and fragmentary teeth from the Kimmeridgian of Poland, England and Switzerland.

[3][11] Fossils from the Western Interior Seaway suggest that it preferred nearshore marine environments, being absent from deeper-water areas, with it likely also being able to tolerate brackish and freshwater conditions.

[7] In the Gulf Coastal Plain, Meristodonoides teeth are largely found in estuarine deposits.

[11] However, some Meristonoides teeth have also been recovered from deep-water deposits representing open marine environments, such as the Northumberland Formation in Canada.