Taxonomic Grouping

BIOL4474 February 2016

Hierarchy in Taxonomy Darwin’s phrase—groups subordinate

to groups Linnaeus' scheme fits evolution fairly well

MacLeay's quinarian system, not so well Circularity Osculant types Insistence on fives

Obligate and Non-obligate Levels of Taxonomy Obligate: KPCOFG Nonobligate levels used when “decided

gaps” appear to occur at more than six levels of grouping

Helpful in large, diverse groups More use in entomology than, say, pogonophorology

p. 187 Schuh and Brower

General Zoology Textbook

HANDOUT—Meylan 1987

Hexapoda (HANDOUT)Class Parainsecta

2 OrdersClass Entognatha

1 OrderClass Insecta

2 Subclasses2 Infraclasses in latter

2 Divisions in latter 2 Superorders in one/3 in other

29 Orders total

Monotypic Taxa and Name Proliferation Monotypic taxa arise when a branch of the

tree of life experiences much extinction and/or little cladogenesis

Name redundancy Ex: Monotypic Lissemydini sister to

Cyclanorbini, with 4 spp.

Lissemydini = Lissemys punctata

Monotypic Taxa (examples) Phylum Placozoa,

Trichoplax adhaerens Division Ginkgophyta,

Ginkgo biloba Order Tubulidentata

Family Orycteropodidae Orycteropus afer

Order Rhynchocephalia Family Sphenodontidae

Sphenodon punctatus and S. guntheri

Monotypic Taxa (more examples) 2 of 29 insect orders are

monofamilial Some nonobligate groups

have only one subordinate group

7 of 24 swallowtail genera are monotypic

526 total species; 204 in type genus Papilio

3 of 10 salamander families are monogeneric

1 of 5 caecilian families is monogeneric

8 of 27 frog and toad families are monogeneric; 3 aremonotypic

4 of 13 turtle families are monotypic and thus monogeneric

Monotypic Taxa (more examples) Tuatara are monogeneric 1 of 30 lizard families

monogeneric (Helodermatidae)

5 of 15 snake families monogeneric, 3 monotypic

6 of 12 emydid genera are monotypic 40 total species; 12 in

Graptemys, one in type genus Emys

9 of 14 trionychid genera are monotypic (22 total species)

Monotypic Taxa (one last example)Phylum Cycliphora Funch and

Kristensen, 1995(Symbiont on lobster mouthparts)Class Eucycliophora Funch and Kristensen, 1995 Order Symbiida Funch and Kristensen, 1995 Family Symbiidae Funch and Kristensen, 1995 Genus Symbion Funch and Kristensen, 1995 Species Symbion pandora Funch and Kristensen, 1995

The "Decided Gap" Principle A genus is a group composed of one or

more species that are separated from other genera by a decided gap, the size of which is in inverse ratio to the size of the group

A family is a group composed of one or more genera that are separated from other families by a decided gap, the size of which is in inverse ratio to the size of the group

A new monotypic salamander genus

Five rhino species, four genera

Indian Sumatran White Javan Black Rhinoceros Dicerorhinus Ceratotherium Rhinoceros Diceros unicornis sumatrensis simum sondaicus bicornis

Dundee 1989

Caecilians: Gymnophiona (1831) over Apoda (1804) Apoda used for fishes (1804) well before application to

caecilians (1966)

Dundee 1989

Salamanders: Caudata (1777) priority over Urodela (1845)

Dundee 1989

Frogs and Toads: Anura (1815) although Salientia has priority (1768) Original Salientia included salamanders Ecaudata (1777) has priority but never in use

Dundee 1989

Turtles: Testudines (used by guess who in 1758) has unbeatable priority Chelonia (or rarely, Chelonii) also duplicates genus name Testudinata sometimes used (rarely, of late)

Dundee 1989

Crocodilians: Crocodylia (1953) over Crocodilia (1842) Correct derivation from genus name Crocodylus (1768)

Dundee 1989

Lizards: Sauria (1802) priority over Lacertilia (1842) Saurii (1800) even greater priority, but never used

Dundee 1989

Snakes: Serpentes nearly universal Rare use of alternative, Ophidia

Avise and Johns 1999

Avise and Mitchell 2007

Readings for Next Time Schuh & Brower: None Winston: 323-336 Additional: L through O

L. A classic criticism of the use of subspecies in taxonomy: Wilson, E.O., and W.L. Brown, Jr. 1953. The subspecies concept and its taxonomic application. Systematic Zoology 2:97111.

M. A beginner's guide to phylogeography: Avise, J.C., J. Arnold, R.M. Ball, E. Bermingham, T. Lamb, J.E. Neigel, C. Reeb, and N.C. Saunders. 1987. Intraspecific phylogeography: The mitochondrial DNA bridge between population genetics and systematics. Annual Review of Ecology and Systematics 18:489522.

N. A good example of phylogeography: Artiss, T. 2004. Phylogeography of a facultatively migratory dragonfly, Libellula quadrimaculata (Odonata: Anisoptera). Hydrobiologia 515:225234.

O. Another good example of phylogeography: Sabatino, S.J., and E.J. Routman. 2009. Phylogeography and conservation genetics of the hellbender salamander (Cryptobranchus alleganiensis). Conservation Genetics 10:12351246.