ammonit.ru Палеонтологическия, Paleontology
Логин
Пароль

Регистрация

Забыли пароль?

 | Палеонтология, палеонтологический портал "Аммонит.ру" |   English version of paleontological portal Ammonit.ru |  Места находок | Геохронологическая шкала | Типы окаменелостей |

 | Виртуальный палеонтологический музей | Публикации | Новости палеонтологии | Пользователи  | Палеонтологические тэги |  

lappets

Ammonite lappets - simmetrical lateral protrusions are located on the adult apertures of many Mesozoic ammonite microconchs (likely shells of male ammonites). Long lappets appeared in ammonoids in Early Jurassic simultaneously with prominent sexual dimorphism. Macroconch shells (likely shells of female ammonites) have no lappets. Many Jurassic and Cretaceous ammonoid taxa had lappets, whereas in several evolutionary lineages of ammonites the lappets gradually dissapeared (especially in Boreal and Subboreal ammonites). The lappets help paleontologists easily distinguish microconchs from macroconch shells. The lack of lappets in many Boreal taxa create a problem: it is very hard to distinguish micro- and macroconch shells in such a situation, because the size of small macroconchs and large microconchs can be nearly identical.

The text was added by: Alex

Самые популярные фотографии, связанные с этим ключевым словом: / Most popular photos related with this paleontological keyword:

Anaplanulites submutatus (Nikitin) Sutneria.(Аммонит 115) Sutneria eumela Anaplanulites difficilis Buckman Anaplanulites submutatus (Nikitin) с устьем Spiticeras obliquelobatum с устьем Микроконх.

Смотреть все фото по этому тэгу >>> // See all photos with this keyword >>>

С ключевым словом "lappets" связаны:

Following items are related with the keyword
"lappets":

137 фотографий

6 публикаций

Ключевые слова, связанные со словом "lappets":
Keywords, related with "lappets":

A: Ammonites

M: Microconchs

А: аммониты

М: микроконхи

У: устье | ушки

Постоянный адрес тэга:
Permanent link:

HTML-ссылка на тэг:
HTML-link to this page: