| Basic info | Taxonomic history | Classification | Included Taxa |
| Morphology | Ecology and taphonomy | External Literature Search | Age range and collections |
Umbilia caepa
Taxonomy
Umbilia caepa was named by Yates (2008) [= 1890 Cypraea leptorhyncha McCoy; Tate, p. 208.]. Its type specimen is SAM P42967, a shell, and it is a 3D body fossil. Its type locality is Murray River cliff, 6 kilometers south of Morgan, which is in a Langhian marine marl in the Cadell Marl Formation of Australia.
Synonymy list
| Year | Name and author |
|---|---|
| 2008 | Umbilia caepa Yates pp. 354 - 358 figs. 1A–G; 2; 3A, C, E, G |
Is something missing? Join the Paleobiology Database and enter the data
|
|
If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.
†Umbilia caepa Yates 2008
show all | hide all
Diagnosis
| Reference | Diagnosis | |
|---|---|---|
| A. M. Yates 2008 | Small pyriform Umbilia distinguished from other species in the genus by the following combination of characters: broadest point of the shell one-third of the length from the posterior end. Plate-like posterior columellar callus separated from labial margin of the posterior canal by a deep notch. Weakly developed dentition with the collumellar dentition effaced from the posterior region. No columellar teeth extending anterior to the fossula. Fossula well developed for the genus. Broadly flanged anterior rostrum lacking dorsal ornamentation.
Shell small for the genus (Table 1), thin and pyriform, with the widest point about one-third of the shell length from the posterior end. The spire is deeply umbilicate and is not callused, being covered only by a thin glaze (Fig. 1C, G). The protoconch is large (1.6 mm in diameter), smooth and domed, and consists of 2.5 whorls. Its axis is slightly tilted relative to the teleoconch. There are three teleoconch whorls. The anterior end extends into a narrow rostrum. Broad but thin flanges extend from the base on each side of the anterior rostrum. The dorsal surface of the rostrum is smooth, bearing no trace of the oblique groove, or the paired tubercles that are usually present in other species of Umbilia, including U. leptorhycha. The posterior canal is very short and is strongly curved to the left in ventral view. A tall, thin, semicircular, plate-like, columellar callus bounds the posterior canal on the left (Fig. 1A, B). The posterior siphonal notch is deeply incised so that there is almost no dorsal roof over the posterior canal (Fig. 1A). There are no flanges supporting the posterior rostrum but the lateral margin of the labral side of the posterior rostrum has a thickened margin as there is in U. leptorhyncha. This thickened margin is much shallower dorsoventrally than in U. leptorhyncha (Fig. 1C, G; 3E, F). The aperture is sinuous and is narrowest at the level of the greatest width of the shell. The outer lip bears 24–27 rather poorly developed short teeth that are most strongly developed in the anterior region, behind the anterior rostrum. The outer lip teeth diminish and disappear at the base of the posterior beak. The inner lip bears 13– 17 short, widely spaced columellar teeth. Three to eight of these teeth are strongly developed at the level of the fossula, and the rest are weakly developed; indeed those in the posterior half diminish to near absence. One or two slightly stronger teeth occur just before the base of the columellar callus but none extend onto it. The fossula is well developed for the genus (Fig. 2). It is smooth and no columellar teeth extend onto it. It is concave and slightly widened in the middle, as opposed to continuously tapering towards the anterior end as in other Umbilia species (except U. leptorhyncha). The inner margin is thickened and lacks an indentation but does bear a small, low tubercle near its anterior end. |
Measurements
No measurements are available
|
|
||||
|
|||||
|
|
||||
|
|||||
|
|
||||
| Source: f = family, c = class | |||||
| References: Kiessling 2004, Hendy et al. 2009 | |||||