Pyktes: An Unsual-Looking Late Cretaceous Gastropod

Popenoe (1983) discovered, named, and illustrated the aporrhaid-gastropod genus Pyktes triphyllon, which has a very distinctive shape because it has two unusual-looking lateral projections of its shell. These lateral projections resemble boxing gloves, hence the derivation of the generic name–Pyktes, which is Greek, for a boxer or pugilist. This species, which is of middle Late Cretaceous age (i.e., late Santonian Stage) is found on the east side of Sacramento Valley, northern California. This gastropod was probably a shallow water, normal-marine, sandy bottom dweller.

Tracings made by me of two views of Popenoe’s photographs of the holotype (= the primary specimen used used by Popenoe (1983) to define his Pyktes: apertural (front) and abapertural (back) views, in successive order. The holotype has a height of 29.3 mm.

According to Popenoe (1983), the genus Pyktes is found also in younger Cretaceous rocks elsewhere in northern California and in the Rocky Mountains. According to Kiel and Bandel (1999), Pyktes occurs also in Late Cretaceous (Santonian Stage) rocks in South Africa.

References

Kiel, S. and K. Bandel. 1999. The Pugnellidae, a new stromboidean family (Gastropod) from the Upper Cretaceous. Palaontologische Zeitschrift 73 (1/2):47–58.

Popenoe, W.P. 1983. Cretaceous Aporrhaidae from California: Aporrhainae and Arrhoginae. Journal of Paleontolgy 57(4)742–765.

CROCODYLIANS USED TO LIVE IN SOUTHERN CALIFORNIA

Fragmentary fossils of crocodylians from 13 formations, ranging in geologic age from the Paleocene to the late Miocene (including seven Eocene units) in southern California, were discussed by Barboza et al. (2017). 

In one of my previous blogs (Feb. 3, 2020)—entitled “How to tell the modern crocodilians apart,” I briefly mentioned the presence of Eocene crocodilian teeth from a single Eocene locality in the San Diego area.

I checked online and discovered a note (with a photograph) about the recent discovery in the San Diego region of partial skeletal remains [including the bony armor that ran along the back of the animal, portions of the front limb and foot, lumbar, and tail vertebrae, and ribs], making it the most complete fossil crocodile known from San Diego. Previous discoveries in the region are restricted to only isolated teeth and bony armor. The animal is believed to belong to the genus Borealosuchus, which is distantly related to modern crocodiles and alligators. (Anonymous). 

Two crocodilian teeth from the middle Eocene Santiago Formation in the Oceanside area of San Diego County, southern California. The specimen on the left is 16 mm height; the one the right is 1.7 cm length. Both sides of these minute teeth have fine serrations (especially along the left side of the larger specimen).

REFERENCES CITED

Anonymous. Year (not given). Featured fossil: an ancient crocodile. https//www.sdnhm.org/blog/blog_details/featured-fossil-an-ancient-crocodile/43/

Barboza, M.M., et al. 2017. The age of the Oso Member, Capistrano Formation, and a review of fossil crocodylians from California. PaleoBios 34:1–16. [pdf is free]

AN ANCIENT GASTROPOD GENUS (WITH A CONFUSING NAME) LIVES ON 

Tudicla lived in tropical, shallow-marine communities during the Late Cretaceous and Paleogene (Paleocene and Eocene). Through time, it decreased both in diversity and geographical range. Today, it is believed to be represented by only a single species, Tudicla spirillus (Linnaeus, 1767), known only from depths of 10–20 m, in sandy bottoms off southeastern India and Sri Lanka (Harasewych, 2018). This species is also the type species of the genus of Tudicla. The taxonomy relationships of this genus, however, have been subject of considerable conflicting interpretations. Also, Tudicla has been variously assigned to at least five different families by modern workers.

[note: Tudicla is not the same gastropod as Tudicula H. an A. Adams, but the similarity between these two separate gastropods still causes some confusion]. 

Front and back views of Tudicla spirillus (height [58 mm (2.5 inches), width 36 mm (1.5 inches)] from southeastern India.

Reference Cited:

Harasewych, M.G. 2018. The anatomy of Tudicla spirillus (Linnaeus, 1767) and the relationships of the Tudiclidae (Gastropoda: Neogastropoda). The Nautilus 132(2):35–44. 

SOME  PRAYING MANTID INSECTS FROM Southern California 

Most modern-day authorities refer to these insects as “praying” mantis, not as “preying” mantis. The word “mantis” in Greek means “prophet,” thus the spelling as “praying” is justified. Nevethess, the mantis is an excellent predator, thus the “preying” name is also very appropriate. So who knows what they will be called in the future? According to Wikipedia (2024), there are 2,500 species, 460 genera and 33 families of mantids (also called mantises). 

The oldest fossil record of mantids [Santamantis axelrodi] is known from northeast of Brazil and is Late Early Cretaceous (110 million years) in age [Albian Stage], thus predating the appearance of the dinosaur Tyrannosaurus rex. Fossil mantids occur in amber. These early mantids are closely related to cockroaches and most likely descended from them.

Three mantid specimens I found in my garden are shown below:

?Iris oratoria, (an adult, 3.5 inches length), from leaf/bark litter, Southern California. This specimen is the “Mediterranean mantis,” which was introduced into California from the Mediterranean area, probably in the 1930’s. 

Stagommantis californica [green variety], (1 and 1/2 inches length), this species is native to the western United States.

Juvenile mantis (0.5 inches length), identification indeterminate, Southern California.

The praying mantis is the only insect in the world that can turn its head nearly 180° (similar to an owl). They have excellent vision, and they are the only invertebrate that can see in 3D. They have five eyes plus three smaller eyes that can detect only light and motion. Also, the praying mantis is among the giants of the insect world and can be up 4 inches in length.

The praying mantis is an ambush predator, and they will eat anything they can; including small-sized reptiles, amphibians, birds, and mice. The praying mantis can jump forward and catch food in its forelegs, which are called “raptorial legs.” Some of the leg segments contain interlocking spines that make it impossible for the prey to escape, once caught. Reportedly, they can give a person a hurtful bite, so, if you must, handle them carefully. But, they are not venomous. The praying mantis eats other insects, especially beetles, crickets, caterpillers, moths, aphids, etc.

 

They are masters of camouflage. They can green, brown, or both in order to blend in with their surroundings. They like to live in gardens and shrubbery.

Four species of praying mantis are known to live in Southern California, and one of these was accidentally introduced from the Mediterranean region (Hogue, 2015). 

References: 

Hogue, C. [revised by J.N. Hogue]. 2016. Insects of the Los Angeles Basin, 3^rd ed. Natural History Museum of Los Angeles County. 477 pp.

Wikipedia 2024 (www.en.wikipedia.org)

Calcitrapessa leeana (Dall, 1890) An Unusual Muricid Gastropod

This species, known as a fossil in the Pleistocene of southern California, also lives today in the Gulf of California. Originally, this species was assigned to genus Calcitrapessa, but then for many years, workers began identifying it as genus Pteropurpura. It is now, however, known once again as Calcitrapessa leeana (Dall, 1890).

Many years ago, I was fortunate enough to find four specimens of this gastropod in an upper Pleistocene terrace deposit near the campus of Loyola College in Los Angeles. The specimens were easily freed from their sedimentary matrix. Sadly, this outcrop and surrounding area have since then been completely destroyed by “development."

According to the website WoRMS (2024), the classification of genus Calcitrapessa is:

Class Gastropod

Order Neogastropoda

Family Muricidae

Subfamily Ocenebrinae

Genus Calcitrapessa

Tuskes and Tuskes (2016) reported this species as Pteropurpura leeana and that it lives today off the west coast (Pacific side) of Baja California, primarily from Cedros Island south to Magdalena Bay. They reported also that these living specimens of P. leeana are only “infrequently collected,” usually by dredging (depths about 180 m) or by tangle nets. They also reported that the shells of leeana are the most divergent (i.e., different) when compared to other species belonging to the muricid family of gastropods. The northernmost known occurrence of a Recent (i.e., modern-day) specimen of P. leeana is Anacapa Island, and that specimen was found in 1941.

The largest fossil specimen that I found (illustrated below) is 6.5 cm [about 2.5 inches] in length and 4 cm [1.5 inches] in width. The tips of the stout spines on the last (body) whorl of this specimen are unfortunately missing, but otherwise preservation is excellent. 

Front and back, of a Pleistocene specimen of Calcitrapessa leeana from a now bull-dozed terrace deposit near Loyola College in Los Angeles. Length 6.5 cm [about 2.5 inches] and width 4 cm [1.5 inches].

Tuskes, P. and A. Tuskes. 2016. Native Pteropurpura of the eastern Pacific (Muricidae). The Festivus 48(4), pp. 211–220.