Are the SUBCLASSES /orders (monotremes/marsupials/eutherians) all there, or are there lost subclasses/orders?
If I understand the question (which I’m not sure I do), some of the points to answer it are: – Any grouping above the species level (and be aware that the species level is also quite discussed/challenged) is arbitrary. Putting taxa together is something that we scientists love to do, but the characters chosen to define each do indeed vary and therefore the classification is dynamic. Taxa are moved from one position to other if there are good reasons to do so. – There are many species (and in paleontology, a “species” can be a single specimen or fragment) whose position in the current phylogenetic tree is not known or uncertain. Usually their affinities can be discerned to some point, and they are labeled as “incerta sedis” which means “of uncertain taxonomic position”. – There are entire groups of mammals whose members went extinct and are only known from fossils. You won’t hear from them in most general Vertebrate classes; for instance the Allotheria (Multituberculates) stem mammals (
Related Questions
- I purchased Starters Orders 4 and have lost my key and have now bought a new computer or reformatted my hard drive etc. How do I get the game working again?
- Are the SUBCLASSES /orders (monotremes/marsupials/eutherians) all there, or are there lost subclasses/orders?
- What are the characteristics of monotremes, mammals, and marsupials?
