| Condonella | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Subclass: | Heterobranchia |
| Superorder: | Eupulmonata |
| Order: | Stylommatophora |
| Family: | Eucalodiidae |
| Genus: | † Condonella McLellan, 1927 [1] |
| Species: | †C. suciensis |
| Binomial name | |
| †Condonella suciensis McLellan, 1927 [1] | |
Condonella is an extinct genus of land snail in the family Urocoptidae known from the fossil species Condonella suciensis of Western North America.
C. suciensis is known from a single internal mold fossil found in north-western Washington state. [2] The holotype specimen was collected on Sucia Island from the south side of Fossil Bay in a group of rock described as "Haslam fossiliferous shale". The area was stated by Roy Davidson McLellan to be fossil rich and Ward in 1978 assigned the strata to the Campanian age Cedar District Formation. The strata preserve what is thought to have been a shallow marine shelf environment that also had ammonites and inoceramid bivalves. [3] The formation has also preserved fossils of other terrestrial organisms including a basal cornalean flowering plant, Suciacarpa starrii and a theropod femur, the first dinosaur identified from Washington State. [3] [4] There is differing opinion regarding what latitude the Cedar district Formation sediments were deposited at in the Campanian. One suggestion, the Baja—British Columbia hypothesis, is that in the Cretaceous the area was located at about 30° north latitude, similar to Modern Baja California, and subsequent tectonic movement has shifted the area 3,000 km (1,900 mi) north to its present-day location. The other suggestion also involves northward tectonic movement, but suggests the Cretaceous location for the sediments was approximately the region of Northern California. [4]
C. suciensis was first described by McLellan in his 1927 Geology of the San Juan Islands based on the single fossil recovered during field work for his thesis. [1] The genus name Condonella was chosen to honor Herbert T. Condon, then the comptroller of the University of Washington, while no etymology was given for the species name suciensis. McLellan noted that the fossil had been examined by paleontologists Timothy William Stanton and William Healey Dall, who both mentioned the shell was similar to those of genus Planorbis freshwater snails. [2] [1] He did not feel that it was likely to be related to Planorbis based on its preservation in marine sediments however, and did not place it into any specific gastropod order. [1] The holotype fossil was reexamined in 1999 by Barry Roth of the University of California, who noted the shell thickness and uniform nature is similar to many non-marine pulmonate gastropods. The fine sculpturing on the exterior of the shell, along with the tight coiling of the shell whorl is most similar to modern members of the land snail family Urocoptidae, and most particularly Eucalodiinae genera, which Roth called "Eucalodiidae". [5]
The holotype fossil has a flat to low spired shell with 6.25 whorls preserved and a diameter of 13.7 mm (0.54 in), though the adult whorls are not preserved. The spire is low, with the outer whorls being higher than the inner whorls, giving a sunken look to the shell center. Numerous fine suture lines curve across most of the shell, fading as the lines approach the keel. Each of the suture lines curve outward toward the aperture. [2]
Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 1927.
Urocoptidae is a family of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the superfamily Urocoptoidea.
Cerionidae is a family of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the superfamily Urocoptoidea.
Clavosurcula sibogae is a species of sea snail, a marine gastropod mollusk in the family Cochlespiridae.
Toxiclionella haliplex is a species of sea snail, a marine gastropod mollusk in the family Clavatulidae.
Fusiturris pluteata is a species of sea snail, a marine gastropod mollusk in the family Fusiturridae.
Fusiturris torta is a species of sea snail, a marine gastropod mollusk in the family Fusiturridae.
Fenimorea moseri is a species of sea snail, a marine gastropod mollusk in the family Drilliidae.
Calliclava alcmene is a species of sea snail, a marine gastropod mollusk in the family Drilliidae.
Calliclava palmeri is a species of sea snail, a marine gastropod mollusk in the family Drilliidae.
Clathrodrillia orellana is a species of sea snail, a marine gastropod mollusk in the family Drilliidae.
The Cedar District Formation is a geologic formation exposed on Vancouver Island, the Gulf Islands of British Columbia and San Juan Islands of Washington (state). It preserves fossils dating back to the Campanian Epoch of the Cretaceous period. It dates to the lower mid-Campanian.
Sibogasyrinx pyramidalis is a species of sea snail, a marine gastropod mollusk in the family Cochlespiridae.
Clathrodrillia dolana is a species of sea snail, a marine gastropod mollusk in the family Drilliidae.
Clathrodrillia callianira is a species of sea snail, a marine gastropod mollusc in the family Drilliidae.
Clavus albotuberculatus is a species of sea snail, a marine gastropod mollusk in the family Drilliidae.
Clavus moquinianus is a species of sea snail in the family Drilliidae.
Suciacarpa is an extinct genus of asterid flowering plants in the order Cornales. It is known from the fossil species Suciacarpa starrii and Suciacarpa xiangae, both found in Western North America.
Hindsiclava calligonoides is an extinct species of sea snail, a marine gastropod mollusc in the family Pseudomelatomidae, the turrids and allies.
The Kristianstad Basin is a Cretaceous-age structural basin and geological formation in northeastern Skåne, the southernmost province of Sweden. The basin extends from Hanöbukten, a bay in the Baltic Sea, in the east to the town of Hässleholm in the west and ends with the two horsts Linderödsåsen and Nävlingeåsen in the south. The basin's northern boundary is more diffuse and there are several outlying portions of Cretaceous-age sediments. During the Cretaceous, the region was a shallow subtropical to temperate inland sea and archipelago.