Scaldicetus
From Wikipedia, the free encyclopedia
| Scaldicetus | |
|---|---|
 | |
| Scaldicetus grandis teeth | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Artiodactyla |
| Infraorder: | Cetacea |
| Superfamily: | Physeteroidea |
| Family: | Physeteridae |
| Genus: | †Scaldicetus Du Bus, 1867 |
| Species | |
| |
| Synonyms[2][3] | |
|
List of synonyms
| |
Scaldicetus is an extinct genus of highly predatory macroraptorial sperm whale. Although widely used for a number of extinct physeterids with primitive dental morphology consisting of enameled teeth, Scaldicetus as generally recognized appears to be a wastebasket taxon filled with more-or-less unrelated primitive sperm whales.[4]
Scaldicetus is known from the Miocene to Pleistocene deposits of Western Europe, the U.S. (California, Florida, Maryland, Virginia), Baja Peninsula, Peru, New South Wales, and Japan.[5] However, Scaldicetus is probably a grade taxon, and fossil teeth assigned to it (largely due to the lack of distinguishing characteristics in fossil teeth alone) probably represent more-or-less unrelated sperm whales united by their primitive characteristics rather than actual ancestry.[4] Consequently, this would inflate the genus's distribution.[5]
The name Scaldicetus caretti was coined in 1867 from numerous sperm whale teeth collected in Neogene deposits near Antwerp, Belgium[6] probably from the early-to-middle Miocene Bercham Formation. However, some of these remains may have been reworked and redeposited into younger rocks. More remains also near Antwerp from the Diest Formation date to the Tortonian (late Miocene).[7]
Synonyms of Scaldicetus include Palaeodelphis, Homocetus, and Eucetus. The genus Physodon described by French paleontologist Paul Gervais in 1872 was previously considered a synonym, but it was declared a nomen dubium in 2006.[8]
Scaldicetus is sometimes classified into the dubious subfamily Hoplocetinae along with Diaphorocetus, Idiorophus, and Hoplocetus based on the presence of large, robust, enamel-coated teeth. The macroraptorial sperm whales Livyatan, Zygophyseter, Brygmophyseter, and Acrophyseter potentially also belong to this subfamily.[5]
"Ontocetus" oxymycterus, described from the middle Miocene (Langhian) of Santa Barbara, California, was assigned to Scaldicetus in 2008,[9] but was subsequently made the type of a new genus, Albicetus.[10]
Description
Unlike the modern sperm whale which only has teeth on the bottom jaw, Scaldicetus had teeth in both jaws. The lectotype for S. caretti had at least 45 teeth in total in its mouth in life. Like other macroraptorial sperm whales but unlike the modern sperm whale, the teeth were covered in a thick enamel coating, about 1.2–1.3 mm (0.047–0.051 in) thick. The teeth were moderately curved and were deeply rooted into the skull, implying a strong bite.[7]
Like in other sperm whales, tooth dimensions vary widely; for the lectotype: the total length of the tooth root (the part of the tooth beneath the gum line) is between 106.9–203.5 mm (4.21–8.01 in) and the maximum total length of the entire tooth is 233 mm (9.2 in). Like in other macroraptorial sperm whales, tooth size increased from the back of the jaw to the front. The maximum diameter of the crown (the part of the tooth that is visible and erupts from the gum line) ranges from 16–32.5 mm (0.63–1.28 in), and diameter was greatest midway up the tooth.[7]
Scaldicetus caretti is 7–12 meters (23–39 ft) long. This is similar in length to a modern female Physeter macrocephalus.[11] Scaldicetus grandis is likely 6.5–7 meters (21–23 ft) long. [citation needed]
