The 12th edition of was the last edition of to be overseen by its author, Carl Linnaeus. It was published in three volumes, with parts appearing from 1766 to 1768. It contains many species not covered in the previous edition, the 10th edition

10th edition of Systema Naturae

The 10th edition of Systema Naturae was a book written by Carl Linnaeus and published in two volumes in 1758 and 1759, which marks the starting point of zoological nomenclature...

, and was for some time the starting point for zoological nomenclature.

Starting point

Only five editions of were written by Linnaeus himself, namely the first, second, sixth, tenth and twelfth. When a "starting point" for zoological nomenclature was first considered, in the Strickland Code of 1843, the 12th edition of was chosen, so that any names which Linnaeus had altered from previous editions would be recorded in their final state. It was later replaced by the 10th edition

10th edition of Systema Naturae

The 10th edition of Systema Naturae was a book written by Carl Linnaeus and published in two volumes in 1758 and 1759, which marks the starting point of zoological nomenclature...

 as the starting point for most zoological nomenclature. The starting point for most names in botanical nomenclature

Botanical nomenclature

Botanical nomenclature is the formal, scientific naming of plants. It is related to, but distinct from taxonomy. Plant taxonomy is concerned with grouping and classifying plants; botanical nomenclature then provides names for the results of this process. The starting point for modern botanical...

 is the 1753 work .

Format

Linnaeus divided the 12th edition into three volumes, the first of which was published in two parts. Volume 1 covered – the animal

Animal

Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...

 kingdom – with the first 532 pages appearing as Part 1 in 1766, and pages 533–1327 appearing as Part 2 in 1767. Volume 2 covered – the plant

Plant

Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...

 kingdom; it comprised 736 pages and appeared in 1767, with an additional 142-page . Volume 3 covered – the mineral kingdom – and appendices

Addendum

An addendum, in general, is an addition required to be made to a document by its reader subsequent to its printing or publication. It comes from the Latin verbal phrase addendum est, being the gerundive form of the verb addo, addere, addidi, additum, "to give to, add to", meaning " must be added"...

 to all three volumes; it comprised 236 pages and was published in 1768. Including appendices, front matter and back matter, the three volumes cover around 2,400 pages.

Novelties

Many species were included in the 12th edition which had not been included in earlier editions. For example, Linnaeus had included 700 species of mollusc

Mollusca

The Mollusca , common name molluscs or mollusksSpelled mollusks in the USA, see reasons given in Rosenberg's ; for the spelling mollusc see the reasons given by , is a large phylum of invertebrate animals. There are around 85,000 recognized extant species of molluscs. Mollusca is the largest...

 in the 10th edition, and added a further 100 species for the 12th edition. Similarly, the number of bird

Bird

Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...

 species in the 12th edition was twice the number in the 10th edition. Sponges were included in the 12th edition, in the class "Zoophyta", having been omitted from previous editions. The 12th edition also included the hundred insect species published separately in , and omitted a claim which Linnaeus had made in earlier editions, that new species do not form, implicitly allowing speciation

Speciation

Speciation is the evolutionary process by which new biological species arise. The biologist Orator F. Cook seems to have been the first to coin the term 'speciation' for the splitting of lineages or 'cladogenesis,' as opposed to 'anagenesis' or 'phyletic evolution' occurring within lineages...

.