Invertebrate paleontology (also spelled invertebrate palaeontology) is sometimes described as invertebrate paleozoology or invertebrate paleobiology.
Whether it is considered to be a subfield of
paleontology,
paleozoology
Palaeozoology, also spelled as Paleozoology ( Greek: παλαιόν, ''palaeon'' "old" and ζῷον, ''zoon'' "animal"), is the branch of paleontology, paleobiology, or zoology dealing with the recovery and identification of multicellular a ...
, or
paleobiology, this discipline is the
scientific study of
prehistoric invertebrate
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chorda ...
s by analyzing
invertebrate
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chorda ...
fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...
s in the
geologic record.
By ''invertebrates'' are meant the ''non-vertebrate'' creatures of the
kingdom Animalia (or
Metazoa
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage in ...
) in the
biotic domain
Domain may refer to:
Mathematics
*Domain of a function, the set of input values for which the (total) function is defined
** Domain of definition of a partial function
** Natural domain of a partial function
**Domain of holomorphy of a function
* ...
of
Eukaryota. By
phyletic definition, these
many-celled, ''sub-vertebrate'' animals lack a
vertebral column,
spinal column,
vertebrae,
backbone, or long, full-length
notochord—in contrast to the
vertebrates in the one phylum of
Chordata.
Relatedly, invertebrates have never had a
cartilaginous or
bone
A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, ...
y internal
skeleton, with its
skeletal supports,
gill slit
Gill slits are individual openings to gills, i.e., multiple gill arches, which lack a single outer cover. Such gills are characteristic of cartilaginous fish such as sharks and rays, as well as deep-branching vertebrates such as lampreys. In co ...
s,
rib
In vertebrate anatomy, ribs ( la, costae) are the long curved bones which form the rib cage, part of the axial skeleton. In most tetrapods, ribs surround the chest, enabling the lungs to expand and thus facilitate breathing by expanding the ches ...
s and
jaws. Finally, throughout
geologic time, invertebrates have remained non-
craniate creatures; that is, they never developed a
cranium,
nerve-chord brain
A brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as Visual perception, vision. I ...
,
skull, or hard protective
braincase (unlike many vertebrates).
Invertebrate terminology in science
In the many decades since
Jean-Baptiste de Lamarck
Jean-Baptiste Pierre Antoine de Monet, chevalier de Lamarck (1 August 1744 – 18 December 1829), often known simply as Lamarck (; ), was a French naturalist, biologist, academic, and soldier. He was an early proponent of the idea that biolog ...
, a pioneering
biologist and
evolutionist, first conceptualized and coined the category "
Invertebrata
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...
" (between 1793 and 1801) and the term "
Biology
Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that process hereditary ...
" (in 1802),
zoology
Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the animal kingdom, including the structure, embryology, evolution, classification, habits, an ...
has come to recognize that the ''non-vertebrate'' category is not a
scientifically valid,
monophyletic taxon.
Evolutionary biology
Evolutionary biology is the subfield of biology that studies the evolutionary processes (natural selection, common descent, speciation) that produced the diversity of life on Earth. It is also defined as the study of the history of life ...
and
developmental biology (a.k.a. "
evo-devo") now consider the term "Invertebrata" to be both
polyphyletic and
paraphyletic. Nevertheless, most
earth science departments continue to employ this term; and
paleontologists find it both useful and practical in evaluating fossil invertebrates and—consequently—invertebrate evolution.
However, there is one contemporary caveat:
Paleobiologists and
microbiologists in the 21st century no longer
classify one-celled "animal-like"
microbes ''either'' as
invertebrate
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chorda ...
s ''or'' as
animal
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage ...
s.
For example, the commonly
fossilized foraminifera ("forams") and
radiolarians—
zooplankton both formerly grouped under either an animal phylum or animal sub-kingdom called
Protozoa ("first animals")—are now placed in the kingdom or super-kingdom
Protista
A protist () is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor (the last eukaryotic common ancestor), the e ...
or
Protoctista
A protist () is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor (the last eukaryotic common ancestor), the exclu ...
(and thus called ''protists'' or ''protoctists'').
Thus modern invertebrate paleontologists deal largely with fossils of this more strictly defined
Animal
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage ...
Kingdom (excepting
Phylum Chordata), Phylum Chordata being the exclusive focus of
vertebrate paleontology.
Protist
A protist () is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor (the last eukaryotic common ancestor), the e ...
fossils are then the main focus of
micropaleontology, while plant fossils are the chief focus
paleobotany. Together these four represent the traditional taxonomic divisions of
paleontologic
Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (geology), epoch (roughly 11,700 years before present). It includes t ...
study.
Origins and modern evolution
Invertebrate fossilization
When it comes to the fossil record, ''soft-''bodied and ''minuscule'' invertebrates—such as
hydras
''Hydra'' ( ) is a genus of small, freshwater organisms of the phylum Cnidaria and class Hydrozoa. They are native to the temperate and tropical regions. The genus was named by Linnaeus in 1758 after the Hydra, which was the many-headed beas ...
,
jellies,
flatworms,
hairworms,
nematodes,
ribbon worm
Nemertea is a phylum of animals also known as ribbon worms or proboscis worms, consisting of 1300 known species. Most ribbon worms are very slim, usually only a few millimeters wide, although a few have relatively short but wide bodies. Many h ...
s,
rotifers and
roundworms—are infrequently
fossilized. As a result,
paleontologists and other
fossil hunters must often rely on
trace fossils,
microfossils, or
chemofossil residue when scouting for these prehistoric creatures.
''Hard-''bodied and ''large'' invertebrates are much more commonly preserved; typically as sizeable
macrofossils. These invertebrates are more frequently preserved because their hard parts fossilise more readily—for example,
shell,
armor, plates,
test
Test(s), testing, or TEST may refer to:
* Test (assessment), an educational assessment intended to measure the respondents' knowledge or other abilities
Arts and entertainment
* ''Test'' (2013 film), an American film
* ''Test'' (2014 film), ...
s,
exoskeleton
An exoskeleton (from Greek ''éxō'' "outer" and ''skeletós'' "skeleton") is an external skeleton that supports and protects an animal's body, in contrast to an internal skeleton ( endoskeleton) in for example, a human. In usage, some of the ...
,
jaws or
teeth
A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, ...
. In invertebrates, these parts are composed of
silica
Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is ...
(
silicon dioxide),
calcite or
aragonite (both forms of
calcium carbonate),
chitin (a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...
often infused with
tricalcium phosphate), or
keratin
Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. Alpha-keratin (α-keratin) is a type of keratin found in vertebrates. It is the key structural material making up Scale (anatomy), scales, hair, Nail ...
(an even-more complex
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...
), rather than the vertebrate
bone
A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, ...
(
hydroxyapatite) or
cartilage of
fish
Fish are Aquatic animal, aquatic, craniate, gill-bearing animals that lack Limb (anatomy), limbs with Digit (anatomy), digits. Included in this definition are the living hagfish, lampreys, and Chondrichthyes, cartilaginous and bony fish as we ...
es and land-dwelling
tetrapods.
The
chitinous
Chitin ( C8 H13 O5 N)n ( ) is a long-chain polymer of ''N''-acetylglucosamine, an amide derivative of glucose. Chitin is probably the second most abundant polysaccharide in nature (behind only cellulose); an estimated 1 billion tons of chiti ...
jaws of
annelids (such as the marine
scolecodonts
A scolecodont is the jaw of a polychaete annelid, a common type of fossil-producing segmented worm useful in invertebrate paleontology. Scolecodonts are common and diverse microfossils, which range from the Cambrian period (around half a billion ...
) are sometimes preserved as fossils; while many
arthropod
Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and cuticle made of chiti ...
s and
inarticulate brachiopods have easily fossilized hard parts of
calcite,
chitin, or
keratin
Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. Alpha-keratin (α-keratin) is a type of keratin found in vertebrates. It is the key structural material making up Scale (anatomy), scales, hair, Nail ...
. The most common and often-found macrofossils are the very hard
calcareous shells of
articulate brachiopods (that is, the everyday "
lampshells") and of
mollusk
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...
s (such as the omnipresent
clams,
snail
A snail is, in loose terms, a shelled gastropod. The name is most often applied to land snails, terrestrial pulmonate gastropod molluscs. However, the common name ''snail'' is also used for most of the members of the molluscan class ...
s,
mussels and
oyster
Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but not ...
s). On the other hand, shell-less
slugs and non-tubiferous
worm
Worms are many different distantly related bilateral animals that typically have a long cylindrical tube-like body, no limbs, and no eyes (though not always).
Worms vary in size from microscopic to over in length for marine polychaete wor ...
s (for instance,
earthworms) lack hard parts and therefore such organisms are poorly represented in the fossil record.
Taxonomy of commonly fossilised invertebrates
Footnotes
Further reading
Although these books are ''not'' footnoted in this article, the following are well-illustrated, well-organized—and often well-worn—guides to invertebrate (and sometimes other) fossils:
* Paolo Arduini (1987), ''Simon and Schuster's Guide to Fossils'' (Old Tappan, New Jersey:
Fireside), 320 pages. .
*
James R. Beerbower (1968). ''Search for the Past: An Introduction to Paleontology'' (Englewood Cliffs, New Jersey:
Prentice-Hall), 512 pages.
* R. S. Boardman and others (1985). ''Fossil Invertebrates''.
*
British Museum of Natural History (1969). ''British Palaeozoic Fossils'' (London, England: British Museum of Natural History).
* Euan N. K. Clarkson (1998). ''Invertebrate Palaeontology and Evolution'' (London, England:
Allen and Unwin
George Allen & Unwin was a British publishing company formed in 1911 when Sir Stanley Unwin purchased a controlling interest in George Allen & Co. It went on to become one of the leading publishers of the twentieth century and to establish an ...
), 468 pages. .
* Peter Doyle (1996), ''Understanding Fossils: An Introduction to Invertebrate Paleontology'' (Hoboken, New Jersey:
John Wiley & Sons
John Wiley & Sons, Inc., commonly known as Wiley (), is an American multinational publishing company founded in 1807 that focuses on academic publishing and instructional materials. The company produces books, journals, and encyclopedias, i ...
), 426 pages. .
*
Carroll Lane Fenton
Carroll Lane Fenton (February 12, 1900, Butler County, Iowa – November 16, 1969, New Brunswick, New Jersey) was a geologist, paleontologist, neoichnologist, and historian of science. Fenton was the author and illustrator of numerous books on ...
and
Mildred Adams Fenton
Mildred Adams Fenton (November 14, 1899 – December 7, 1995) trained in paleontology and geology at the University of Iowa. She coauthored dozens of general science books with her husband, Carroll Lane Fenton, including ''Records of Evolution' ...
(1958); updated by Patricia Vickers Rich and Thomas Hewitt Rich (1997). ''The Fossil Book: A Record of Prehistoric Life'' (Garden City, New York:
Doubleday and
Courier Dover Publishing), from 482 to 760 pages. .
* W. R. Hamilton and others (1974). ''A Guide to Minerals, Rocks and Fossils'' (London, England:
Hamlyn Publishing Group Ltd.), 320 pages.
*
W. B. Harland (1967). ''The Fossil Record'' (London, England:
Geological Society of London), 827 pages.
* V. Lehmann and G. Hillmer (1983). ''Fossil Invertebrates'' (Cambridge, England:
Cambridge University Press
Cambridge University Press is the university press of the University of Cambridge. Granted letters patent by King Henry VIII in 1534, it is the oldest university press in the world. It is also the King's Printer.
Cambridge University Pr ...
).
* Harold L. Levin (1998), ''Ancient Invertebrates and Their Living Relatives'' (Boston:
Prentice-Hall), 358 pages. .
* William H. Matthews III (1962). ''Fossils: An Introduction to Prehistoric Life'' (New York:
Barnes & Noble), 337 pages.
* Helmut Mayr (1992). ''A Guide to Fossils'' (New York:
Longman, Harlow).
*
Raymond C. Moore and others (1952). ''Invertebrate Fossils'' (New York:
McGraw-Hill
McGraw Hill is an American educational publishing company and one of the "big three" educational publishers that publishes educational content, software, and services for pre-K through postgraduate education. The company also publishes refere ...
), 776 pages. .
* J. W. Murray, editor (1985). ''Atlas of Invertebrate Macrofossils'' (Princeton:
Princeton University Press
Princeton University Press is an independent publisher with close connections to Princeton University. Its mission is to disseminate scholarship within academia and society at large.
The press was founded by Whitney Darrow, with the financial ...
), 256 pages.
*
Douglas Palmer (2004), ''Fossils'' (London, England:
Dorling Kindersley
Dorling Kindersley Limited (branded as DK) is a British multinational publishing company specialising in illustrated reference books for adults and children in 63 languages.
It is part of Penguin Random House, a subsidiary of German media c ...
).
* Frank H. T. Rhodes and others (1962). ''Fossils: A Guide to Prehistoric Life'' (New York:
Golden Nature Guide), 242 pages.
*
Henry Woodburn Shimer and
Robert Rakes Shrock (1944/1983). ''Index Fossils of North America'' (Cambridge, Massachusetts:
Massachusetts Institute of Technology Press
The MIT Press is a university press affiliated with the Massachusetts Institute of Technology (MIT) in Cambridge, Massachusetts (United States). It was established in 1962.
History
The MIT Press traces its origins back to 1926 when MIT publis ...
), 837 pages.
* Robert Rakes Shrock and W. H. Twenhofel (1953). ''Invertebrate Paleontology'' (New York: McGraw-Hill).
* Ronald Singer (2000), ''
Encyclopedia of Paleontology'' (London, England:
Routledge
Routledge () is a British multinational publisher. It was founded in 1836 by George Routledge, and specialises in providing academic books, journals and online resources in the fields of the humanities, behavioural science, education, law ...
), 1,467 pages. .
*
Ida Thompson (1982/2004). ''
National Audubon Society Field Guide to North American Fossils'' (New York:
Alfred A. Knopf
Alfred A. Knopf, Inc. () is an American publishing house that was founded by Alfred A. Knopf Sr. and Blanche Knopf in 1915. Blanche and Alfred traveled abroad regularly and were known for publishing European, Asian, and Latin American writers i ...
), 846 pages.
*
James W. Valentine
James William Valentine (November 10, 1926 – April 7, 2023) was an American evolutionary biologist, Professor Emeritus in the Department of Integrative Biology at the University of California, Berkeley, and curator at the University of Calif ...
(2004), ''On the Origins of Phyla'' (Chicago: University of Chicago Press). 608 pages. . A discussion focusing on invertebrates during the Paleozoic era.
*
Cyril Walker and
David Ward (2002). ''Smithsonian Handbook of Fossils'' (London, England: Dorling Kindersley), 320 pages.
External links
A colorful, illustrated taxonomy of extinct ''and'' living invertebrate Metazoaby the
University of California Museum of Paleontology.
The invertebrate fossil record illustrated colorfully for Metazoaprovided by the U.C. Museum of Paleontology.
Educational and colorful introduction to the three domains of the Tree of Life– as well as to the topic of "Understanding Evolution" – sponsored by the U.C. Museum of Paleontology.
An introduction to fossilsby
The Paleontology Portal, a project of four American institutions funded by the
National Science Foundation
The National Science Foundation (NSF) is an independent agency of the United States government that supports fundamental research and education in all the non-medical fields of science and engineering. Its medical counterpart is the National ...
.
The introduction to ''invertebrate'' fossilsprovided by The Paleontology Portal.
Thousands of online pictures of invertebrate fossils.sponsored by the
Peabody Museum at
Yale University
Yale University is a private research university in New Haven, Connecticut. Established in 1701 as the Collegiate School, it is the third-oldest institution of higher education in the United States and among the most prestigious in the w ...
.
The taxonomy of the Metazoa Kingdom of animalsprovided by
The Tree of Life Project.
Home siteof the many volumes of the ''
Treatise on Invertebrate Paleontology
The ''Treatise on Invertebrate Paleontology'' (or ''TIP'') published by the Geological Society of America and the University of Kansas Press, is a definitive multi-authored work of some 50 volumes, written by more than 300 paleontologists, and ...
'', a site sponsored by both
The Paleontological Institute at the
University of Kansas and the
Geological Society of America
The Geological Society of America (GSA) is a nonprofit organization dedicated to the advancement of the geosciences.
History
The society was founded in Ithaca, New York, in 1888 by Alexander Winchell, John J. Stevenson, Charles H. Hitch ...
.
{{DEFAULTSORT:Invertebrate Paleontology