A redescription of Tesseraspis mosaica Karatajute-Talimaa, 1983 (Vertebrata: Pteraspidomorphi: Heterostraci) from the Lochkovian (Lower Devonian) of Severnaya Zemlya, Russia, with a review of tessellated heterostracan taxa

Alain Blieck, David K Elliott, Valentina N. Karatajute-Talimaa

Research output: Contribution to journalReview article

Abstract

Material of tesseraspids (Tesseraspidiformes) is reported from the uppermost Severnaya Zemlya Formation (Lochkovian, Lower Devonian) of the Severnaya Zemlya archipelago, in the Russian Arctic, where it is associated with other vertebrate remains, including corvaspids, acanthodians, and large but rare specimens of osteostracans. The tesseraspid material is not abundant, and most often preserved as a "patchwork" of bony platelets (tesserae), except for a few partly articulated specimens. We redescribe the holotype of Tesseraspis mosaica Karatajute-Talimaa, 1983, whose head carapace is preserved as a flattened tube of adjacent tesserae. This material is compared to the already published tesseraspid taxa, i.e., T. tessellata Wills, 1935, T. toombsi Tarlo, 1964, T. mutabilis (Brotzen, 1934), T. oervigi Tarlo, 1964 emend. Dineley and Loeffler, 1976, T. denisoni Tarlo, 1964, and T. talimaae Tarlo, 1965. All species are based upon rare and incomplete material, as no head carapaces associated with trunk and tail are known, and so, the intraspecific variability is also unknown. Distinction between "species" is based on the detail of the superficial sculpture of the tesserae of the head carapaces, which is unsatisfactory. It is concluded that only four of the nominal species can be retained. A review of all other known tessellated pteraspidomorphs indicates that our knowledge of tessellated heterostracans is currently insufficient to support a meaningful classification.

Original languageEnglish (US)
Pages (from-to)275-306
Number of pages32
JournalActa Geologica Polonica
Volume68
Issue number3
DOIs
StatePublished - Jan 1 2018

Fingerprint

Lochkovian
archipelago
vertebrate
material

Keywords

  • Comparative anatomy
  • Lochkovian
  • Severnaya Zemlya
  • Systematic review
  • Tessellated heterostracans
  • Tesseraspidiformes

ASJC Scopus subject areas

  • Geology

Cite this

@article{bed7a8b1c4c54ee49213c15be5e6ca32,
title = "A redescription of Tesseraspis mosaica Karatajute-Talimaa, 1983 (Vertebrata: Pteraspidomorphi: Heterostraci) from the Lochkovian (Lower Devonian) of Severnaya Zemlya, Russia, with a review of tessellated heterostracan taxa",
abstract = "Material of tesseraspids (Tesseraspidiformes) is reported from the uppermost Severnaya Zemlya Formation (Lochkovian, Lower Devonian) of the Severnaya Zemlya archipelago, in the Russian Arctic, where it is associated with other vertebrate remains, including corvaspids, acanthodians, and large but rare specimens of osteostracans. The tesseraspid material is not abundant, and most often preserved as a {"}patchwork{"} of bony platelets (tesserae), except for a few partly articulated specimens. We redescribe the holotype of Tesseraspis mosaica Karatajute-Talimaa, 1983, whose head carapace is preserved as a flattened tube of adjacent tesserae. This material is compared to the already published tesseraspid taxa, i.e., T. tessellata Wills, 1935, T. toombsi Tarlo, 1964, T. mutabilis (Brotzen, 1934), T. oervigi Tarlo, 1964 emend. Dineley and Loeffler, 1976, T. denisoni Tarlo, 1964, and T. talimaae Tarlo, 1965. All species are based upon rare and incomplete material, as no head carapaces associated with trunk and tail are known, and so, the intraspecific variability is also unknown. Distinction between {"}species{"} is based on the detail of the superficial sculpture of the tesserae of the head carapaces, which is unsatisfactory. It is concluded that only four of the nominal species can be retained. A review of all other known tessellated pteraspidomorphs indicates that our knowledge of tessellated heterostracans is currently insufficient to support a meaningful classification.",
keywords = "Comparative anatomy, Lochkovian, Severnaya Zemlya, Systematic review, Tessellated heterostracans, Tesseraspidiformes",
author = "Alain Blieck and Elliott, {David K} and Karatajute-Talimaa, {Valentina N.}",
year = "2018",
month = "1",
day = "1",
doi = "10.1515/agp-2018-0024",
language = "English (US)",
volume = "68",
pages = "275--306",
journal = "Acta Geologica Polonica",
issn = "0001-5709",
publisher = "Wydawnictwo Naukowe INVIT",
number = "3",

}

TY - JOUR

T1 - A redescription of Tesseraspis mosaica Karatajute-Talimaa, 1983 (Vertebrata

T2 - Acta Geologica Polonica

AU - Blieck, Alain

AU - Elliott, David K

AU - Karatajute-Talimaa, Valentina N.

PY - 2018/1/1

Y1 - 2018/1/1

N2 - Material of tesseraspids (Tesseraspidiformes) is reported from the uppermost Severnaya Zemlya Formation (Lochkovian, Lower Devonian) of the Severnaya Zemlya archipelago, in the Russian Arctic, where it is associated with other vertebrate remains, including corvaspids, acanthodians, and large but rare specimens of osteostracans. The tesseraspid material is not abundant, and most often preserved as a "patchwork" of bony platelets (tesserae), except for a few partly articulated specimens. We redescribe the holotype of Tesseraspis mosaica Karatajute-Talimaa, 1983, whose head carapace is preserved as a flattened tube of adjacent tesserae. This material is compared to the already published tesseraspid taxa, i.e., T. tessellata Wills, 1935, T. toombsi Tarlo, 1964, T. mutabilis (Brotzen, 1934), T. oervigi Tarlo, 1964 emend. Dineley and Loeffler, 1976, T. denisoni Tarlo, 1964, and T. talimaae Tarlo, 1965. All species are based upon rare and incomplete material, as no head carapaces associated with trunk and tail are known, and so, the intraspecific variability is also unknown. Distinction between "species" is based on the detail of the superficial sculpture of the tesserae of the head carapaces, which is unsatisfactory. It is concluded that only four of the nominal species can be retained. A review of all other known tessellated pteraspidomorphs indicates that our knowledge of tessellated heterostracans is currently insufficient to support a meaningful classification.

AB - Material of tesseraspids (Tesseraspidiformes) is reported from the uppermost Severnaya Zemlya Formation (Lochkovian, Lower Devonian) of the Severnaya Zemlya archipelago, in the Russian Arctic, where it is associated with other vertebrate remains, including corvaspids, acanthodians, and large but rare specimens of osteostracans. The tesseraspid material is not abundant, and most often preserved as a "patchwork" of bony platelets (tesserae), except for a few partly articulated specimens. We redescribe the holotype of Tesseraspis mosaica Karatajute-Talimaa, 1983, whose head carapace is preserved as a flattened tube of adjacent tesserae. This material is compared to the already published tesseraspid taxa, i.e., T. tessellata Wills, 1935, T. toombsi Tarlo, 1964, T. mutabilis (Brotzen, 1934), T. oervigi Tarlo, 1964 emend. Dineley and Loeffler, 1976, T. denisoni Tarlo, 1964, and T. talimaae Tarlo, 1965. All species are based upon rare and incomplete material, as no head carapaces associated with trunk and tail are known, and so, the intraspecific variability is also unknown. Distinction between "species" is based on the detail of the superficial sculpture of the tesserae of the head carapaces, which is unsatisfactory. It is concluded that only four of the nominal species can be retained. A review of all other known tessellated pteraspidomorphs indicates that our knowledge of tessellated heterostracans is currently insufficient to support a meaningful classification.

KW - Comparative anatomy

KW - Lochkovian

KW - Severnaya Zemlya

KW - Systematic review

KW - Tessellated heterostracans

KW - Tesseraspidiformes

UR - http://www.scopus.com/inward/record.url?scp=85054601687&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85054601687&partnerID=8YFLogxK

U2 - 10.1515/agp-2018-0024

DO - 10.1515/agp-2018-0024

M3 - Review article

VL - 68

SP - 275

EP - 306

JO - Acta Geologica Polonica

JF - Acta Geologica Polonica

SN - 0001-5709

IS - 3

ER -