Ischnochitonidae

Ischnochiton australis, copyright Nuytsia@Tas.

Belongs within: Ischnochitonina.
Contains: Stenoplax (Stenoradsia).

The Ischnochitonidae are a group of chitons in which the dorsum of the intermediate valves is divided into distinct lateral and central areas, often by a diagonal rib (Smith 1960).

Characters (from Smith 1960): Ovate to elongate chitons of variable size. Tegmentum of intermediate valves divided into lateral and central areas by diagonal rib (commonly indistinct) extending from apex to anterior outer angle of valves on each side. Articulamentum of head and tail valves multiple-slitted, that of intermediate valves with single slit or in some groups with two or more slits on each side. Teeth sharp-edged, not pectinated, grooved, or buttressed on outside. Eaves not porous. Sutural laminae sharp and well developed.

<==Ischnochitonidae
    |--Oligochiton Berry 1922 S60
    |    `--*O. lioplax Berry 1922 S60
    |--Tonicina Thiele 1906 S60
    |    `--*T. zschaui (Pfeffer 1886) [=Chiton zschaui] S60
    |--Basiliochiton Berry 1918 [incl. Lophochiton Berry 1925 non Ashby 1923, Ploiochiton Berry 1926] S60
    |    |--*B. heathii (Pilsbry 1898) [=Mopalia heathii] S60
    |    `--B. lobium Berry 1925 O27
    |--Gurjanovillia Jakoleva 1952 F77
    |    |--*G. albrechti (Schrenck 1867) [=Chiton albrechti] F77
    |    `--G. lindberghi Jakovleva 1952 F77
    |--Cyanoplax Pilsbry 1892 [incl. Mopaliella Thiele 1909, Mopaliopsis Thiele 1893] S60
    |    |--*C. hartwegii (Carpenter 1855) S60 (see below for synonymy)
    |    |    |--C. h. hartwegii O27
    |    |    `--C. h. nuttalli (Carpenter 1855) [=Chiton nuttalli, Lepidochitona (Cyanoplax) hartwegii nuttalli] O27
    |    |--C. fackenthallae Berry 1919 [=Lepidochitona (Cyanoplax) fackenthallae] O27
    |    |--C. lowei (Pilsbry 1918) [=Trachydermon lowei, Lepidochitona (Cyanoplax) lowei] O27
    |    `--C. raymondi (Pilsbry 1894) [=Trachydermon (Cyanoplax) raymondi, Lepidochitona (C.) raymondi] O27
    |--Stenoplax Carpenter in Dall 1879 S60
    |    |  i. s.: S. circumsenta Berry 1956 PP78
    |    |         S. heathiana GW02
    |    |--S. (Stenoplax) S60
    |    |    |--*S. (S.) limaciformis (Sowerby 1832) [=Chiton limaciformis] S60
    |    |    |--S. (S.) biarcuata (Dall 1903) [=Ischnochiton (Stenoplax) biarcuata] O27
    |    |    |--S. (S.) conspicua (Carpenter in Pilsbry 1892) S60, O27 [=Ischnochiton (Stenoradsia) conspicuus O27]
    |    |    `--S. (S.) fallax (Carpenter 1892) [=Ischnochiton (Stenoplax) fallax] O27
    |    |--S. (Stenochiton Adams & Angas 1864) [incl. Zostericola Ashby 1919] S60
    |    |    `--S. (*S.) juloides (Adams & Angas 1864) [=*Stenochiton juloides] S60
    |    `--S. (Stenoradsia) S60
    |--Lepidozona Pilsbry 1892 F77 (see below for synonymy)
    |    |--*L. mertensii (Millendorff 1847) F77 [=Chiton mertensii F77, Ischnochiton (Lepidopleurus) mertensii O27, C64]
    |    |--L. asthenes (Berry 1919) [=Ischnochiton (Lepidozona) asthenes] O27
    |    |--L. californiensis S60
    |    |--L. clathrata (Reeve 1847) SF77 [=Chiton clathratus O27, Ischnochiton (Lepidozona) clathratus O27]
    |    |--L. cooperi (Carpenter in Pilsbry 1892) [=Ischnochiton (Lepidozona) cooperi] O27
    |    |    |--L. c. cooperi O27
    |    |    `--L. c. acutior (Carpenter in Dall 1919) [=Ischnochiton (Lepidozona) cooperi acutior] O27
    |    |--L. crockeri (Willett in Hertlein & Strong 1951) PP78
    |    |--L. decipiens (Carpenter 1892) [=Ischnochiton (Lepidozona) decipiens] O27
    |    |--L. formosa Ferreira 1974 PP78
    |    |--L. golischi (Berry 1919) [=Ischnochiton (Lepidozona) golischi] O27
    |    |--L. ima Sirenko 1975 F77
    |    |--L. multigranosa Sirenko 1975 F77
    |    |--L. serrata (Carpenter 1864) PP78
    |    |--L. sinudentata (Carpenter 1892) [=Ischnochiton (Lepidozona) sinudentatus] O27
    |    |--L. stearnsii (Dall 1902) [=Ischnochiton (Lepidozona) stearnsii] O27
    |    |--L. thielei Sirenko 1975 F77
    |    `--L. willetti (Berry 1917) [=Ischnochiton (Lepidozona) willetti] O27
    `--Ischnochiton Gray 1847 SF77 (see below for synonymy)
         |  i. s.: I. adelaidensis (Reeve 1847) [=Chiton adelaidensis] H09
         |         I. allyni Ferreira 1977 F77
         |         I. beanii C64
         |         I. circumvallatus (Reeve 1847) P61
         |         I. comptus GO06
         |         I. elenensis C64
         |         I. granulifer Thiele 1909 P61
         |         I. limaciformis C64
         |         I. luteoroseus Suter 1907 P61
         |         I. magdalensis [incl. Chiton giganteus Tilesius 1824 (nom. inv.)] C64
         |         I. maorianus Iredale 1914 P61
         |         I. marloffsteinensis Fieldel & Keupp 1988 BE93
         |         I. mawsoni Cotton 1937 P61
         |         ‘Callochiton’ mortenseni Odhner 1924 F27
         |         I. parallelus C64
         |         ‘Chiton’ platessa [=*Levicoplax platessa] F27
         |         I. prasinatus C64
         |         I. punctulatissimus VN05
         |--I. (Ischnochiton) F77
         |    |--*I. (I.) crispus (Reeve 1847) [=Chiton crispus] F77
         |    |--I. (I.) longicymba O27
         |    |--I. (I.) numantius S60
         |    |--I. (I.) spiculosus S60
         |    `--I. (I.) textilis (Gray 1828) S60 [=Chiton textilis P61]
         |--I. (Anisoradsia Iredale & May 1916) S60
         |    `--I. (*A.) mawlei Iredale & May 1916 S60
         |--I. (Autochiton Iredale & Hull 1924) S60
         |    `--I. (*A.) torri Iredale & May 1916 S60
         |--I. (Chondropleura Thiele 1906) S60
         |    `--I. (*C.) exaratus (Sars 1878) [=Lophyrus exaratus] S60
         |--I. (Euporoplax Iredale & Hull 1924) S60
         |    `--I. (*E.) virgatus (Reeve 1847) [=Chiton virgatus] S60
         |--I. (Euretoplax Iredale & Hull 1924) S60
         |    `--I. (*E.) wilsoni Sykes 1896 S60
         |--I. (Haploplax Pilsbry 1894) (see below for synonymy) S60
         |    `--I. (*H.) smaragdinus (Angas 1867) [=Lophyrus smaragdinus] S60
         |--I. (Heterozona Carpenter in Dall 1879) S60
         |    `--I. (*H.) cariosus Carpenter in Pilsbry 1892 S60
         |--I. (Ischnoplax Carpenter in Dall 1879) S60
         |    `--I. (*I.) pectinatus (Sowerby 1840) S60 [=Chiton pectinatus S60]
         |--I. (Ischnoradsia Shuttleworth 1853) [incl. Lepidoradsia Carpenter in Dall 1879] S60
         |    `--I. (*I.) australis (Sowerby 1840) [=Chiton australis] S60
         |--I. (Isochiton Ashby & Cotton 1934) S60
         |    `--I. (*I.) bardwelli Ashby & Cotton 1934 S60
         |--I. (Lophyropsis Thiele 1893) S60
         |    `--I. (*L.) imitator (Smith 1881) [=Chiton (Ischnochiton) imitatrix] S60
         |--I. (Ovatoplax Cotton & Weeding 1939) S60
         |    `--I. (*O.) mayi Pilsbry 1895 [=I. (Haploplax) mayi] S60
         |--I. (Radsiella Pilsbry 1892) S60
         |    `--I. (*R.) tridentatus Pilsbry 1893 SF77
         |--I. (Rhodoplax Thiele 1893) SF77
         |    |--I. (R.) striolatus (Gray 1828) [incl. Chiton squamulosus Adams 1845, *Rhodoplax squamulosus] SF77
         |    |--I. (R.) eucosmius Dall 1919 SF77 [=Radsiella eucosmius PP78]
         |    `--I. (R.) petaloides (Gould 1846) (see below for synonymy) SF77
         |--I. (Rhombochiton Berry 1919) S60
         |    `--I. (*R.) regularis (Carpenter 1855) [=Chiton regularis] S60
         |--I. (Stenosemus Middendorff 1847) [incl. Lepidopleuroides Thiele 1893] S60
         |    `--I. (*S.) albus (Linné 1767) [=Chiton albus] S60
         |--I. (Strigichiton Hull 1923) S60
         |    `--I. (*S.) verconis Torr 1911 S60
         `--I. (Tripoplax Berry 1919) F77 [incl. Ischnoradsia Carpenter in Dall 1879 non Shuttleworth 1853 S60]
              `--I. (*T.) trifidus (Carpenter 1864) F77 [=Trachydermon trifidus S60]

*Cyanoplax hartwegii (Carpenter 1855) S60 [=Chiton hartwegii S60, Ischnochiton hartwegii C64, Lepidochitona (Cyanoplax) hartwegii O27]

Ischnochiton Gray 1847 SF77 [incl. Beanella Thiele 1893 non Dall 1882 S60, Diktuonus Ashby 1931 S60, Lepidochiton Carpenter 1857 S60, Leptopleura Thiele 1893 S60, Levicoplax Iredale & Hull 1925 S60, Lophyriscus Thiele 1893 S60, Stereoplax Thiele 1893 S60]

Ischnochiton (Haploplax Pilsbry 1894) [incl. Chartoplax Iredale & Hull 1924, Radsiella Thiele 1893 non Pilsbry 1892] S60

Ischnochiton (Rhodoplax) petaloides (Gould 1846) [=Chiton petaloides, Radsiella petaloides; incl. Ischnochiton mariposa Dall 1919] SF77

Lepidozona Pilsbry 1892 F77 [incl. Lepidopleurus Carpenter in Dall 1879 nec Risso 1826 nec Claparède 1868 S60, Solivaga Iredale & Hull 1925 S60]

*Type species of generic name indicated

REFERENCES

[BE93] Benton, M. J., & D. H. Erwin. 1993. Mollusca: Amphineura and ‘Monoplacophora’. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 125–130. Chapman & Hall: London.

[C64] Carpenter, P. P. 1864. Supplementary report on the present state of our knowledge with regard to the Mollusca of the west coast of North America. Report of the British Association for the Advancement of Science 33: 517–686.

[F77] Ferreira, A. J. 1977. A new species of chiton from the Aleutian Islands (Mollusca: Polyplacophora). Veliger 20 (1): 27–29.

[F27] Finlay, H. J. 1927. A further commentary on New Zealand molluscan systematics. Transactions and Proceedings of the New Zealand Institute 57: 320–485.

[GO06] Giribet, G., A. Okusu, A. R. Lindgren, S. W. Huff, M. Schrödl & M. K. Nishiguchi. 2006. Evidence for a clade composed of molluscs with serially repeated structures: monoplacophorans are related to chitons. Proceedings of the National Academy of Sciences of the USA 103 (20): 7723–7728.

[GW02] Giribet, G., & W. Wheeler. 2002. On bivalve phylogeny: a high-level analysis of the Bivalvia (Mollusca) based on combined morphology and DNA sequence data. Invertebrate Biology 121 (4): 271–324.

[H09] Hedley, C. 1909. The Marine Fauna of Queensland: Address by the President of Section D. Australasian Association for the Advancement of Science: Brisbane.

[O27] Oldroyd, I. S. 1927. The Marine Shells of the West Coast of North America vol. 2 pt 3. Stanford University Press: Stanford University (California).

[PP78] Poorman, F. L., & L. H. Poorman. 1978. Additional molluscan records from Bahía de Los Angeles, Baja California Norte. Veliger 20 (4): 369–374.

[P61] Powell, A. W. B. 1961. Shells of New Zealand: An illustrated handbook 4^th ed. Whitcombe and Tombs Limited: Christchurch.

[S60] Smith, A. G. 1960. Amphineura. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt I. Mollusca 1: Mollusca—General Features, Scaphopoda, Amphineura, Monoplacophora, Gastropoda—General Features, Archaeogastropoda and some (mainly Paleozoic) Caenogastropoda and Opisthobranchia pp. I41–I76. Geological Society of America, and University of Kansas Press.

[SF77] Smith, A. G., & A. J. Ferreira. 1977. Chiton fauna of the Galápagos Islands. Veliger 20 (2): 82–97.

[VN05] Vinther, J., & C. Nielsen. 2005. The Early Cambrian Halkieria is a mollusc. Zoologica Scripta 34: 81–89.