SOME LEFT-HANDED COILED SEA SHELLS

             

This post is # 560 in my continuing sequence of blog posts since I began my blog in 2014.

Nearly all gastropod (snail) sea shells are right-hand coiled (dextral), but there are a few species that have left-hand coiled (sinistral). The reason why seashells coil in a left-landed way (sinistral) is related to genetic processes. This blog post illustrates examples of each type of coiling. 

Figure 1. The shallow-marine seashell genus Busycon carica [the so-called “knobbed whelk”] lives in bays and offshore on the east coast of the United States. Most shells of this genus are dextral coiled, like the example shown here: when viewed with the apex of the shell upward, the aperture (opening) in the seashell is on the right. The shell illustrated here is about 17 cm (6.5 inches) in height.

Figure 2. Busycon perversum (the “lightning whelk”). I am not sure what the size of this specimen is, but the maximum height for this species is about 30 cm (13 inches). It lives in nearshore waters on the east coast of the United States. This shell is an example of a sinistral coiled shell. Image from North American Wildlife (1982, p. 246). 

Figure 3. The closely related gastropod Busycotypus canaliculata was introduced in 1938 in the San Francisco area. There is no certain information as to how or exactly when this species reached the west coast, but it possible that it was brought along with oysters or lobsters from other regions (Hanna, 1966, p. 49). The illustrated specimen shown here is dextrally coiled and 16 cm (6.5 inches) in length. This species, which has also been found from Orange County, southern California (L.T. Groves, personal commun.) can have a shell up to 8 inches in height. (Information and photograph kindly provided by Lindsey T. Groves, Collections Manager of Malacology, Los Angeles County, California).

SOME OTHER MARINE SINISTRAL GASTROPODS

Triphora shells, typically 2 to 10 mm in length, are also a sinistral gastropods. For an example, see one of my previous blogs (October 16, 2023).

There are two other extant marine gastropod genera that can have sinistral shells: 1) Sinistralia [in the family Fasciolariidae] and 2) Antiplanes [recently reclassified as being in family Pseudomelatomidae].

I also detected in the literature, two extinct marine gastropod genera that can have sinistral shells. These are the east coast (Virginian to Florida) Conus adersarius, of Plio- Pleistocene age, and also the northern Atlantic Neptunea angulata of Plio-Pleistocene age.

References

Abbott, R.T. and S. Peter Dance. 1982. Compendium of seashells. E.P. Dutton, New York, 410 pp.

Hanna, G D. 1966. Introduced mollusks of western North America. Occasional Papers of the Academy of Sciences, no. 48, 108 pp., 4 pls.

North American Wildlife: An illustrated guide to 2,000 plants and animals. Reader’s Digest, Pleasantville, New York. Editor S. J. Wernert, editor. 615 pp.

Wikipedia, 2026. 

WoRMS (https://marinespecies.org)

ACKNOWLEDGMENTS

Lindsey T. Groves, Collections Manager of Malacology, Los Angeles County, California.

HELICOPRION: AN ANCIENT FISH WITH AN UNUSUAL WHORL OF TEETH

The word, Heliocprion, [pronounced “he-lee-co-pri-on”] translates into “spiral jaw.” This  extinct ocean-dwelling cartilaginous creature has been commonly inferred to be an ancient (but unusual) shark. In actuality, however, it is most closely related to the modern-day chimeroform ratfish (= “ghost sharks”) [which are not sharks.] Some reports say that the body of Helicoprion was bigger than the size of a modern-day "Great White Shark," but because the skeleton of Helicoprion was cartilagnous (i.e. that type of material does not preserve well), a full body of Helicoprion has not been found. 

Heliocprion ranged from early to late middle Permian time (approximately 250 to 275 million years ago) [see Fig.1]. It lived in in ocean waters in Asia, Australia, Europe, and the Americas. The first fossils of this animal were found in 1886, in Western Australia. 

The only part of an Helicoprion that is fossilized is the mineralized (=hard material) tooth whorl. As mentioned above, the rest of its skeleton consisted of soft cartilage. Thus the body shape of Helicoprion is based on inference, not on an actual specimen (see Fig. 2).

The teeth of Helicoprion occur only in its lower jaw, and they occur in tooth whorls (for example: a 23 cm in diameter whorl, with about 117 serrated teeth) [see Fig. 2]. The only remains of Helicoprion are about 100 known examples of these tooth whorls. The teeth occur only in the lower jaw. Unlike sharks, Helicoprion did not shed its teeth; instead, it added them during its lifespan.

Exactly how Helicoprion fed has been the source of many different interpretations. Also, it is likely that they ate squids and fish.

  Classification (via Wikipedia, 2026)

Kingdom Animalia

Phylum Chordata

Class Chondrichthyes

Order Eugeneodontiformes (extinct)

Family Helicoprionidae (extinct)

Genus Helicoprion (extinct: its teeth are unique in that they are arranged in a tooth whorl inside the mouth).

Only three species of Helicoprlion are known.

Figure 1. Geologic time chart. Helicoprion ranged from Permian into Triassic time.

REFERENCE: The URL’s these days are becoming so complicated and long, it is just more simple to do the following: to see an excellent video of this fossil animal, just go to YouTube and type in: Helicoprion. Then, click on Helicoprion: The Buzz Saw Shark.

Figure 2. A sketch of the anterior half of a Helicoprion. 

Two Examples of Primarily, Late Paleozoic Marine-Invertebrate Fossils

These fossils are from the mid-continent region (e.g., Oklahoma, Texas, etc.) of North America. One of the fossils is a calcareous sponge, and the other fossil is a marine gastropod (snail). 

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Example Number 1. The calcareous sponge: Cotyliscus ewersi? See King (1943). Note: Intact sponge fossils are uncommon!

   Classification

Kingdom Animalia

Phylum Porifera

Class Demospongea

Order Agelasilida

Family uncertain 

Genus Catyliscus? 

Type Species: C. ewersi 

Side and top views of a specimen of the calcareous sponge Cotyliscus?. Height 22 mm, diameter 30 mm. [note: Intact Paleozoic sponges, like the one shown here) are uncommon]. For a discussion and images of the type species of Catyliscus, see King (1943, pl. 3, figs. 2 and 3---cited herein, below).

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Example Number 2. The marine gastropod (snail) Worthenina tabulata. It lived during Devonian to Cretaceous time, in marine communities in the mid-continent region of North America, but most of its occurrences are late Paleozoic age. 

   Classification

Kingdom Animalia

Phylum Mollusca

Class Gastropoda

Order Pleurotomaiida

Family Lophospiridae

Genus Worthenina

Type Species: Worthenina tabulata

The geologic time range of this genus is Devonian to Triassic, but most occurrences are of Pennsylanian age.

Front and back views of a specimen of the gastropod (snail) shell of Worthenina tabulata. Height 20 mm, width 20 mm. This turban-shaped shell has a raised ridge along the margin (a so-called slit band) of the whorls. Small nodes occur along the edge of the whorls. The aperture opening of this species is large.

The geologic time range of this genus is Devonian to Triassic, but most occurrences are of Pennsylanian age.

Reference:

King, R. H. 1943. New Carboniferous and Permian sponges. Kansas State Geological Survey Bulletin 47, p. 1-36 [available online and for free].

THREE REPRESENTATIVE AMMONITE FOSSILS FROM WESTERN USA

Ammonites are extinct cephalopods (mollusks) that had soft parts that resembled squids but also had a hard, external shell (used for protection).

1) MIDDLE TRIASSIC NEVADITES AMMONITE FROM WESTERN NEVADA

 

In 1975, I collected specimens of the ceratitid ammonite Nevadites hyatti? (Smith) from anoxic black shale/limestone = the Middle Triassic Prida Formation, which was deposited along the ancient continental coastline that existed at that time.

Fig. 1. Back side of a specimen of the Middle Triassic ammonite Nevadites hyatti from Nevada.

2) UPPER CRETACEOUS SCAPHITES AMMONITE FROM       NORTHWESTERN NW NEW MEXICO

In 1968, when I was a summer field assistant working for Shell Oil Company in northwestern New Mexico, I collected specimens of this ammonite. They occurred only in heavy concretions that had weathered out from nearby cliffs. I had to bust up a representative concretion with a sledge hammer in order to recover any fossils, which were predominantly the ammonite Scaphites sp. Not much time was spent by the crew I was with, when it came to collecting fossils. We were there to measure a stratigraphic section, but the fossiliferous concretions were a wonderful “bonus” for me!

 

These ammonites are of Late Cretaceous age (about 92 million years old, from the Gallup Sandstone, which correlates with Upper Cretaceous Turonian Stage). The ammonites are heteromorphs, meaning that their shell became uncoiled with growth (the uncoiled parts were broken off on the specimens I collected). I identified these ammonite specimens as Scaphites.

Fig. 2. Back side of the Late Cretaceous ammonite Scaphites sp. from northwestern New Mexico.

3) UPPER CRETACEOUS HOPLOSCAPHITES AMMONITE FROM MONTANA

This widespread genus of shallow-marine ammonite was previously reported as confined to Late Cretaceous age rocks. In recent years, however, shallow-marine Hoploscaphites ammonites have been reported in Early Paleocene (Danian Stage) rocks in Denmark, the Netherlands and in the USA. This new information does not support the previous viewpoint held by most earth scientists that all ammonites died out at the end of the Cretaceous Period. 

In North America, Hoploscaphites lived primarily in the Late Cretaceous warm waters of the Western Interior Seaway---from eastern Alaska to northern Mexico. The early part of the shell of this animal was tightly coiled, but with growth the shell became somewhat uncoiled (i.e., J-shaped). This genus has complicated septa (= curved partitions that divide the shell into chambers). 

Overriding the septa are complicated suture lines (white on these images). The suture lines of Holploscaphites are especially complicated  which indicates that this genus was an advanced form of ammonite that lived during Cretaceous time.

Figure 3. Back side of the Late Cretaceous ammonite Hoplocsaphites sp. from Montana (this specimen was a gift given to me).

TWO TOADS

Toads are a type of frog. Toads have bumpy, dry, thick, skin and short legs for hopping or walking on land (thus, they can be terrestrial). Toads lay their eggs in long spiral chains. Toads are also  generally toothless.

Frogs, in contrast,  have smooth, slimy skin and long legs for leaping through water. Frogs live in or near water. They lay their eggs in gooey clusters, and frogs usually have small teeth in their upper jaw.

Biogeographic analyses suggest modern toads originated in South America approximately 61 million years ago (i.e., middle Paleocene, with later dispersal to Africa and Asia (Wu et al., 2025) and Wikipedia, 2025).                                                         

                                  ANAXYRUS TOAD

Two summers ago, I was surprised when I found a toad in my backyard. It is the only one I have every seen in my yard. It was an adult Anaxyrus americanus, which is a North American toad. It was spotted in the morning time, which is unusual because this toad is mainly nocturnal. This toad eats insects, worms, spiders, and slugs.

Its dry, warty skin has prominent parotoid glands behind its eyes, which secrete this toxin milky poison. It skin is brown to gray, with a light stripe that runs down the middle of its back. It has short legs, warty skin, and a stout body about 2 to 4 inches long. It absorbs water through its skin. It periodically shed its old skin. 

   Classification

Kingdom

Phylum Chordata

Class Amphibia

Order Anura

Famil Bufonidae

Genus Anaxyrus

Species A. boreas

[only three species are known]

note: Anaxyrus boreas is found throughout California, except for the northernmost counties 

(californiaherps.com).

Figure 1. Anaxyrus boreas (about 3 inches long), found in my backyard in Southern California.

                        VIETNAMESE MOSSY TOAD

This nocturnal amphibian lives in northern Vietnam and southern China. This toad (usually incorrectly referred to as a "frog,") has excellent camouflage because it has extremely bumpy/mottled moss-like skin that has green and brown coloration (plus some red) that blends in perfectly with the rainforest habitat in which it lives. They require high humidity.

These toads are 2.5 to 3.5 inches in length, with females larger than males. They are also insectivores that mainly eat crickets and cockroaches. These toads defend themselves by curling into a ball and dropping into standing water in the rain forests. Their skin has toxins, thus if you have to handle one, you should wear gloves. 

Classification

Kingdom Animalia

Phylum Chordata

Class Amphibia

Order Anura

Family Rhacophoride

Genus Theloderma

Type Species T. corticale

Figure. Vietnamese Mossy Toad (usually and incorrectly referred to as a "frog") is about 3 inches in length. Image from the Smithsonian Institution (open access).

References: 

californiaherps.com

Wikipedia 2025

Wu, D. and 13 others. 2025. Earth history and trait innovation drive the global radiation of modern toads. Proceedings of the Royal Society B, Biological Sciences, v. 292, issue 2057. Access is via an account. Otherwise, only the abstract can be viewed.

TWO UNUSUAL BUGS

THE IRONCLAD BEETLE

This flightless beetle is native to California and Baja California. It lives up to eight years (note: most beetles live for only a few weeks or months). It has a very hard flat carapace (shell) that is difficult to penetrate, even with a pin: hence, the name “ironclad”. This insect can play dead and go for long periods without food water. It eats rotten wood and any associated fungi in the wood. This beetle has smaller legs than non-boring insects, thus it is more easily burrows into wood.

  Classification

Kingdom Animalia

Phylum Arthropoda

Clade (only one)

Class Insecta

Order Coleoptera

Family Zopheridae

Genus Phloeodes

Type Species P. diabolicus

The adults of this beetle are up to inch long (25 mm). It moves fairly slowly. It spends most of its time living under the bark of a rotting tree. I discovered this beetle in late afternoon as it was slowly “walking” on a sidewalk next to where a partially rotten tree was recently removed by city workers. Ironclad beetles are crepuscular (active an hour or so before sunset).

It was a challenge to identify this insect, but I just kept looking online and in my small collection of “nature books.” I eventually concluded that it had to be a beetle, but there are so many of them! Eventually, via a process of elimination, I concluded that what I found was as “ironclad beetle.” 

Figure 1. Phloeodes diabolicus (about 10 mm long). Santa Clarita, Southern California.  

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MOTTLED STINK BUG

This insect is another species that I had never seen before. It is native to southern Europe. Finding a specimen clinging to the outer wall of my house was even more of a surprise to me, because this insect is supposedly not yet known to occur in the USA. Well, it can reported as definitely occurring there now! Shield bugs have sucking mouth parts that damage crops, thus, it and insects like it are considered to be pests Fichter (1966, p. 70).

The common name for this insect is a “shieldbug.” The large triangular area (or scutellum) at the posterior end of this insect is conspicuous and distinctive for this kind of insect.

Stink bugs do damage, both as nymphs and as adults, by sucking sap from plants and causing them to wilt, and/or to become pimpled or malformed. These bugs also give off a strong order. 

   Classification

Kingdom Animalia

Phylum Arthropoda

Family Pentatomidae

Clade (1 of them)

Class Insecta

Order Hemiptera

Family Pentatomidae

Genus Rhaphigaster

Type Species Rhaphigaster nebulosa

Reference

Fichter, G. S. 1966. Insect Pests. A Golden Nature Guide. Western Publishing Company, New York. 160 pp.

Figure 2. Rhaphigaster nebulosa, 16 mm length, from Santa Clarita, southern California. This specimen has an orange abdomen with tiny black dots on its outer surface.

References

Hogue, C.L. [revised by J.N. Hogue] 2015. Insects of the Los Angeles Basin, 3^rd ed. Natural History Museum of the Los Angeles Basin, 479 pp.

Wikipedia, 2026.

GRAPHIC GRANITE

 
Graphic granite is an igneous rock with a very distinctive texture of intergrown crystals of quartz and alkali feldspar. The rock is white or pink.

Figure 1. Two hand specimens (each about 4 inches tall) of graphic granite collected by the author from San Diego County, southern California. The scale in the image is in centimeters.

The intergrown crystals produce a texture that looks like ancient, angular cuneiform or hieroglyphic script. This disintictive texture is the result of simultaneous crystallization of quartz rods with the host feldspar crystals. 

This kind of rock forms in granitic pegmatives during the simultaneous cooling and crystallization of molten magma saturated with both feldspar and quartz.

Graphic granite is found throughout the world at various locales (e.g., the Rocky Mountains, America).

The name is derived from the Latin grapus and the Greek gryphos---both words meaning to write.

PYGMY CEDAR (AN UNCOMMON PLANT)

Schott’s pygmy cedar (= Peucephyllum schottii) is the only species of this very unusual genus. This plant is not a cedar, a fir, nor a pine. Rather, it is a member of the aster family, Asteraceae. Although I could not find anything about the fossil record of Schott’s pygmy cedar, I am including it in my blog, nevertheless, because of the apparent rarity of the plant. I detected this plant in the front yard of one of my neighbors.

  Figure 1. Schott’s pygmy cedar in bloom (this plant is four feet tall). 

                                                  Figure 2. When this plant is not in bloom.

This uncommon plant belongs to a monotypic genus (e.g., having only a single species). In its modern record, this plant is "at risk."

Its flowers consist of only yellow, disc florets. It has yellow/green needle-like leaves that produce rounded tufts of white, cotton-like material. The fruits of this plant are woody, bristly seeds.

Also known as “Desert fir,” “Desert pine," or "pigmy cedar,” it is heat tolerant and can persist through droughts. It prefers to live in full sunlight on dry rocky slopes, among boulders.

Although native to California, Arizona, Baja California, and Sonora in northern Mexico, it also is found in Nevada and Utah. I came across this plant while walking around my neighborhood. I was fortunate to have detected such an unusual plant, with its odd features.

It is a perennial shrub, that can be up to 9 feet in height. It is an interesting plant that normally grows only in desert environments. 

Its genus name is derived from the Greek work for pine or fir. The tubular flowers of this plant are commonly visited by hummingbirds and/or small mammals (Southwest Desert Flora = a website, see below).

References

Southwest Desert Flora, https://southwesterdesertflora.com

Wikipedia, 2025.

PURPLE SAGE

This plant's common name is well known (e.g., "Riders of the Purple Sage," a popular western book written by Zane Grey). The botanical name of this plant, which is Salvia lecophylla, is not commonly mentioned in popular literature. 

I was really surprised to learn that this perennial shrub is native to the southern coastal mountain ranges of Southern California and Baja Sur California (in Mexico). It is, furthermore, commonly called the San Luis, California “purple sage,” even though it is not very purplish. [Note: it seems to me that the common name “purple sage,” has been over-used) for various species of Salvia].

Salvia lecuophylla is a shrub that can be up to 5 feet tall. Its leaves are light green in spring but turn grayish-white with maturity (when its branches arch toward the ground). Its flowers, which grow in tight whorls, are six to eight inches long. The flowers are white to pinkish-purple and in very widely spaced clusters of lowly elevated, somewhat inflated looking, gray spikes. The flowers can have a few thin threads. The leaves are light-green gray, thick, and pimply. Branches commonly arch toward the ground. [Note: When I returned to the exact same plant, one week later, most of the purple color was gone (those parts had fallen off), thus the plant could then be called the “gray sage.”]

This hardy plant is drought-tolerant and requires low maintenance. It thrives in full sun. It lives in USDA Zones 8-11. It can survive temperatures as low as 0-10 degrees F. It comes back every year, as it is a wood perennial plant. It can also survive with only sparse water. 

It also repels cockroaches (they do not like the “sage” smell). 

   Classification

Kingdom Plantae

Clades (4 of them)

Order Lamiales

Family Laminaceae (= the mint family)

Genus Salvia

Type Species S. leucophylla

There are many cultivares (variants) of this flower, including wild hybrids, thus making clear identification tricky.

Note: Salvia dorrii, which is native to the western-interior of the USA (including Utah), is possibly the plant that Zane Grey had in mind when he gave the title “Riders of the Purple Sage,” to his famous western novel (set in Utah). This novel was also the basis for a movie. He was not precise in the taxonomic usage of this plant, thus there has been on-going disagreement as to which species he had in mind.

                                                                  

Figure 1. A Salvia lecophylla plant (about 3 feet wide) that I found growing wild in Santa Clarita, Southern California. I initially had no idea as to the identification of this flower, and I was very surprised when it became evident that it belonged to the sage family.  

Figure 2. A closeup of a portion of the same plant as shown in Figure 1. Image also   taken on the same day (in early summer) as the one shown in Figure 1, above. One week later, I examined this same plant, and most of the purple color was "gone."