Agnewia kempae

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Agnewia kempae
Temporal range: Late Pleistocene
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Agnewia kempae MA70011-a.jpg
Holotype from Auckland War Memorial Museum
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Subclass: Caenogastropoda
Order: Neogastropoda
Family: Muricidae
Genus: Agnewia
Species:
†A. kempae
Binomial name
†Agnewia kempae

Agnewia kempae is an extinct species of sea snail, a marine gastropod mollusc, in the family Muricidae, the murex snails or rock snails. [1] Fossils of the species date to the Late Pleistocene, and occur in the strata of Te Piki in the eastern Bay of Plenty, New Zealand.

Contents

Description

Reverse view of holotype Agnewia kempae MA70011-b.jpg
Reverse view of holotype

In the original description, Powell described the species as follows:

Shell small, fusiform rather thin. Whorls 8, including a typical four-whorled sinusigera protoconch. Sculpture consisting of broad, low, obscure axial folds crossed by fine, crisp, sharply-raised spiral cords. These cords number five on the first post-nuclear whorl, eight upon the third post-nuclear, twelve upon the penultimate, and about forty upon the body-whorl and base. The interspaces are mostly from one and a-half times to twice the width of the cords. The axials number thirteen per whorl and are most distinct upon the earlier whorls. Spire elevated, conic, about same height as aperture; outline sinuous, generally arcuate, but slightly concave just below suture. Aperture subvertical, narrowly ovate, with a very short, straight and open shallowly notched anterior canal. Parietal and columella callus polished, slightly countersunk. Fasciole defined by a strong rounded ridge and sculptured with fine, closely spaced spiral threads. Outer lip thin and sharp. [2]

The holotype of the species measures 18 mm (0.71 in) in height and 8.5 mm (0.33 in) in diameter. [2] The species has less prominent axials and more widely spaced and sharply raised spirals relative to Agnewia tritoniformis , [2] and has a rounded, protruding nodule on the outer lip similar in appearance to a "stromboid notch", [3] something not found in A. tritoniformis. [4]

The species has short, blunt labral teeth that form at the end of its spinal chord, [5] and is small relative to other members of Muricidae is moderately elongated. [6]

Ecology

The species lived in New Zealand at a time when the climate was much warmer than the current day. [6]

Taxonomy

The species was first described by A.W.B. Powell in 1934, who named the species after the Dory Kemp (née May), wife of Alfred Ernest Kemp, who lived at Cape Runaway. [2] [7] The holotype was collected by Powell in August 1933 from 6 km (3.7 mi) east of Cape Runaway in the Bay of Plenty Region, and is held by the Auckland War Memorial Museum. [8] [9]

The species likely represents a population of Agnewia tritoniformis which spread from Australia, then becoming genetically isolated and evolving into a distinct species. [6] [10] [11]

Distribution

This extinct marine species dates to the Late Pleistocene (Haweran), and is only known to occur in the strata of the Waipaoa Formation (Te Piki Member), in the eastern Bay of Plenty, New Zealand. [8] [11]

References

  1. ↑ Agnewia kempae A. W. B. Powell, 1934 † . 24 November 2025. Retrieved through: World Register of Marine Species .
  2. 1 2 3 4 Powell, A. W. B. (1934). "Upper Pliocene Fossils from Cape Runaway". Records of the Auckland Institute and Museum . 1: 261–274. ISSN   0067-0464. JSTOR   42905956. Wikidata   Q58676565.
  3. ↑ Grant-Mackie, J. A.; Chapman-Smith., M. (1971). "Paleontological notes on the Castlecliffian Te Piki bed, with descriptions of new molluscan taxa". New Zealand journal of geology and geophysics. 14 (4): 655–704. doi:10.1080/00288306.1971.10426328.
  4. ↑ Tan, K. S. (April 2003). "Phylogenetic analysis and taxonomy of some southern Australian and New Zealand Muricidae (Mollusca: Neogastropoda)". Journal of Natural History . 37 (8): 911–1028. doi:10.1080/00222930110120610. ISSN   0022-2933. Wikidata   Q99973009.
  5. ↑ Vermeij, Geerat J. (September 1998). "New genera of Cenozoic muricid gastropods, with comments on the mode of formation of the labral tooth". Journal of Paleontology . 72 (5): 855–864. doi:10.1017/S0022336000027190. ISSN   0022-3360. Wikidata   Q122981441.
  6. 1 2 3 Beu, G.; Raine, J.I. (2009). Revised descriptions of New Zealand Cenozoic Mollusca from Beu and Maxwell (1990). R. GNS Science miscellaneous series no. 27. ISBN   978-0-478-19705-1.
  7. ↑ "Kemp, Alfred Ernest, 1888-1974". National Library of New Zealand . Retrieved 24 November 2025.
  8. 1 2 Blom, Wilma M. (2025). "Annotated Catalogue of Fossil and Extant Molluscan Types in the Auckland War Memorial Museum". Bulletin of the Auckland Museum . 22. doi:10.32912/BULLETIN/22. ISSN   1176-3213. OCLC   1550165130. Wikidata   Q135397912.
  9. ↑ "Agnewia kempae". Collections Online. Auckland War Memorial Museum . Retrieved 24 November 2025.
  10. ↑ Beu, A. G. (24 February 2012). "Marine Mollusca of the last 2 million years in New Zealand. Part 5. Summary". Journal of the Royal Society of New Zealand. 42 (1): 1–47. doi:10.1080/03036758.2011.559727. ISSN   0303-6758. Wikidata   Q54645723.
  11. 1 2 Beu, A. G. (March 2011). "Marine Mollusca of isotope stages of the last 2 million years in New Zealand. Part 4. Gastropoda (Ptenoglossa, Neogastropoda, Heterobranchia)". Journal of the Royal Society of New Zealand. 41 (1): 1–153. doi:10.1080/03036758.2011.548763. ISSN   0303-6758. Wikidata   Q54553193.
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