What are the phyla and classes of animals and their fossil records?

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In summary, there is no single source that provides a comprehensive overview of all animal phyla and classes - both extant and extinct. However, there are many books available that describe the various phyla and their relationships, as well as the evolutionary history of these groups. The use of molecular data has greatly improved our understanding of these relationships, but there are still controversies and unknowns, particularly with regard to the fossil record. Some phyla may have appeared earlier than previously thought, but left few fossils due to their small and soft bodies. The evolution of phyla is also seen as a step-wise process, with increasing complexity in body plans. For plants, "Paleobotany and the Evolution of Plants" by Wilson N. Stewart is a
  • #1
snorkack
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Could you suggest any source giving a good systematic overview of all phyla and classes - extant and extinct?
From
https://en.wikipedia.org/wiki/Phylum
the list of animal phyla is suggested as 34, but controversies exist
Some phyla have no fossil record, some fossilize with great luck, some often fossilize.
While many old fossils are hard to classify and some have been suspected as extinct phyla, there are no generally acknowledged extinct phyla: these suspicious fossils have also been suspected to belong to extinct classes of extant phyla.
No easily fossilized phylum has appeared after Ordovician, and these may have had poorly fossilized members in Cambrian.
Listing phyla:
Easily fossilized:
  1. Cnidaria - since Vendian
  2. Porifera - since Vendian
  3. Annelida - since Cambrian
  4. Arthropoda - since Cambrian
  5. Brachiopoda - since Cambrian
  6. Chaetognatha - since Cambrian
  7. Chordata - since Cambrian
  8. Ctenophora - since Cambrian
  9. Echinodermata - since Cambrian
  10. Entoprocta - since Cambrian
  11. Hemichordata - since Cambrian
  12. Loricifera - since Cambrian
  13. Mollusca - since Cambrian
  14. Nematoda - since Cambrian
  15. Sipuncula - since Cambrian
  16. Tardigrada - since Cambrian
  17. Bryozoa - since Ordovician
With lucky fossilization:
  1. Rotifera - since Eocene
  2. Onychophora - since Cretaceous
  3. Platyhelminthes - since Permian
  4. Priapulida - since Carboniferous
No fossil record:
  1. Cycliophora
  2. Gastrotricha
  3. Gnathostomulida
  4. Kinorhyncha
  5. Micrognathozoa
  6. Nematomorpha
  7. Nemertea
  8. Orthonectida
  9. Phoronida
  10. Placozoa
  11. Rhombozoa
  12. Xenacoelomorpha
 
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Classes:
Cnidaria, since Vendian:
  1. Anthozoa - since Vendian
  2. Stauromedusae - since Vendian
  3. Cubozoa - ill preserved
  4. Hydrozoa - ill preserved
  5. Scyphozoa - ill preserved
  6. Polypodiozoa - ill preserved
  7. Malacosporea - ill preserved
  8. Myxosporea - ill preserved
Porifera, since Vendian (?):
  1. Calcarea - since Cambrian
  2. Hexactinellida - since Cambrian
  3. Demospongia - since Cambrian
  4. Homoscleromorpha - ?
Annelida, since Cambrian:
  1. Polychaeta - since Cambrian
  2. Clitellata - since Triassic
  3. Echiura - since Carboniferous
  4. Machaeridia - Ordovician to Carboniferous
Arthropoda, since Cambrian:
  1. Trilobita - Cambrian to Permian
  2. Arachnida - since Silurian
  3. Merostomata - since Ordovician
 
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  • #3
snorkack said:
Could you suggest any source giving a good systematic overview of all phyla and classes - extant and extinct?
My response is focused on metazoa (multi-cellular animals) since I don't know a lot about plant and fungal phylogeny.

Phyla are taxonomic divisions that arose early in evolution, with body plans which, once established at these early times, were rarely changed except in "details" which generated sub-divisions of phyla like classes.

There are lots of large books (also see) that describe many (but perhaps not all) of the phyla. I would suggest looking through several in a college library. Here is a short article on a few phyla and their relationships. Generally, the larger the books, the more complete will be their coverage the morphological features of the many different phyla. Smaller books might have rather thin discussions of the details of the some phyla. Among animals, they would generally be found under comparative biology or comparative invertebrate biology. These books would include lots of information about the anatomy and physiology of each group or at least the differences between them.

In the last few years, there has been a revolution in the research on phyla, due to the use of sequence data which can easily provide lots and lots (hundreds, thousands, millions) of informative traits for determining their evolutionary relationships. Before that, traits used in phylogenetic analysis were restricted to anatomical, physiological, developmental, and biochemical traits which are way fewer in number and therefore had less power to resolve phylogenetic relationships.
Therefore, if you are interested in understanding the evolutionary relationships between these groups, I would avoid the older books now (although they have good anatomical etc descriptions) because many relationships were not as well resolved as now, due to the limitied data that was available when they were written.

snorkack said:
No easily fossilized phylum has appeared after Ordovician, and these may have had poorly fossilized members in Cambrian.
Most smaller, more recently derived taxa (like classes vs. phyla) should appear after the phyla have been established and would be relatively small changes to the body plan of their particular phyla.
Among the animals, it is commonly assumed that almost all the phyla appeared during the Cambrian or earlier, however, many may not have fossilized well. The many phyla are also assumed to be derived from one (or a few) different precursors in some not entirely known step-wise manner. The relationships between the various phyla should be representative of this ordering of their origins.

Some molecular estimates indicate phyla evolved earlier, but left few if any fossils due to having small soft bodies that rarely leave good fossils. There are also a lot of "enigmatic" fossils from earlier times whose relations to existing phyla are not obvious to everyone. These may be examples of some of these earlier stages which could have lead to current phyla or might have been evolutionary dead ends (died out without leaving descendants).

An Evo-Devo view of phyla would describe them as resulting from a step-wise evolution of the developmental processes (embryology) that generate the diverging set (different phyla) with increasingly more complex body plans.
 
  • #4
(not Discovery magazine) --
For plants you want:
Wilson N. Stewart 'Paleobotany and the Evolution of Plants'
Most college libraries will have a copy. There is a discussion on 'missing' Phyla that is really good.
 
  • #5
Unfortunately, edit rights soon expire. Compiling longer texts is therefore difficult.
Arthropoda, since Cambrian:
  1. Arachnida - since Silurian
  2. Merostomata - since Ordovician
  3. Pycnogonida - since Cambrian
  4. Chilopoda - since Silurian
  5. Diplopoda - since Silurian
  6. Branchiopoda - since Cambrian
  7. Remipedia - since Carboniferous
  8. Maxillopoda - since Cambrian
  9. Ostracoda - since Ordovician
  10. Malacostraca - since Cambrian
  11. Insecta - since Devonian
  12. Pauropoda - ill preserved, since Eocene
  13. Symphyla - ill preserved
  14. Cephalocarida - ill preserved
  15. Entognatha - ill preserved
  16. Trilobita - Cambrian to Permian
  17. Camptophyllia - Carboniferous
  18. Marrellomorpha - Cambrian to Devonian
  19. Acanthomeridion - Cambrian
  20. Thelxiope - Cambrian
Note statistics of arthropods:
Modern diversity is 11 living and easily fossilized classes, plus 4 ill preserved classes.
Fossil diversity is the fossils of 11 extant classes, plus 1 well recognized class (Trilobita) and 4 more mysterious and less represented groups.
 
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FAQ: What are the phyla and classes of animals and their fossil records?

What are the five main phyla in the animal kingdom?

The five main phyla in the animal kingdom are Chordata, Arthropoda, Mollusca, Annelida, and Cnidaria.

What is the difference between a phylum and a class?

A phylum is a broader taxonomic category than a class. Phyla contain classes, and classes contain orders, and so on. Phyla represent a major evolutionary branch, while classes represent a smaller branch within that phylum.

What are the distinguishing characteristics of the phylum Chordata?

The phylum Chordata is characterized by the presence of a notochord, a hollow nerve cord, and pharyngeal slits at some point during their development. It also includes animals with a segmented body plan, a post-anal tail, and a dorsal nerve cord.

What are the main classes within the phylum Arthropoda?

The main classes within the phylum Arthropoda are Insecta, Arachnida, Crustacea, and Myriapoda. These classes are defined by their jointed appendages and segmented bodies, and include animals such as insects, spiders, crustaceans, and millipedes.

What are some examples of animals in the phylum Mollusca?

Some examples of animals in the phylum Mollusca are snails, clams, octopuses, and squids. These animals are characterized by their soft, unsegmented bodies, and most have a hard external shell for protection.

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