A GIANT-SIZED MIOCENE FOSSIL BARNACLE FROM CALIFORNIA

On the west side of the San Joaquin Valley, central California, near the town of Coalinga, outcrops of the shallow-marine Santa Margarita Formation contain locally abundant, giant-sized (several inches tall and wide) barnacle fossils. Identifications as to their genus and species have been inconsistent (Cote, 1991:p.158). Detailed study is needed to resolve their exact generic identification. In one of my previous blog posts (Nov. 11, 2017), I briefly mentioned these large barnacles and photographed the same cluster of specimens that is also used in this current blog post. 

Some specimens of this large (several inches tall and wide) barnacle genus/species have, in a few cases, been misidentified as fragments of mammoth bone or even as rudistid bivalves (note: these particular bivalves went extinct at the end of the Cretaceous). 

Top view of an individual specimen of Tamiosoma gregaria Conrad, from the Santa Margarita Formation, Coalinga area.

Side view of the same specimen.

Basal view of the same specimen.

Top view of a cluster of T. gregaria (7 inches wide and 6 inches tall) from the same locality as the specimens shown above. 

REFERENCE CITED

Cote, Russel. 1991. Paleontology of the Santa Margarita Formation. California State University, Northridge. This master’s thesis is available for free online. 

PONDEROSA LEMON (BIGGEST LEMONS EVER)

The gigantic fruit of the ponderosa “lemon,” or Citrus x pyriformis, is the biggest citrus in the world. It is a hybrid of a pomelo and a citron, thus it is not a true lemon. It was probably derived from a cross between a wild citrus and a domesticated citrus, such as a variety of a bitter orange. It can weight as much as 5 pounds and is often the size of grapefruits. Furthermore, like other citrus, lemons are actually a berry. 

The example shown above is from northern Los Angeles County, southern California. Such plants are not native to this area; they have to be purchased from plant nurseries.

The tree from whence the giant fruit came from (i.e. after it was picked). You can see some regular sized fruit still on the tree.

Some other big "lemons" from the same tree (shown above). Although, these are large, they are not as big as the giant one shown above. These big "lemons" are in the process of growing into giants.

The fossil record of citrus fruit is is poor! The earliest fossils of citrus plants (in general) are of late Miocene age (8 million years ago) and  are found in southwestern China.

Reference Consulted: A blog by Jerry James Stone (2023).

WESTERN SPADEFOOT TOAD, TRANSVERSE RANGES, SOUTHERN CALIFORNIA

While doing geologic field work in the Transverse Ranges, just north of the San Fernando Valley in southern California, one day a few years ago, I came across something I had never encountered before or since. I was way off the “beaten track,” in a “wild” area, when I saw three toads sitting on a rock, next to a small stream–in a shady area. This particular area is not easily accessible to hikers, and that is undoubtedly the reason these toads were present. It is common knowledge that unspoiled “wild areas”) are becoming fewer and fewer these days (and sightings are rare–because of human encroachment. Furthermore, this toads is now considered to be an endangered species in this area, and I was fortunate to be able to see them. In addition, it was rare event because, I spotted them during the day, even though they are primarily nocturnal.

Phylum Vertebrata

Class Amphibia

Family Pelobatidae

Genus Spea [spea is Greek, meaning warty skin]

Species hammondii

Spea hammondii is a small (1.5 to 2.5 inches long) stout-bodied toad with short legs and warty skin. Their eyes are wide-set, with no bone buildup (boss) in between them. Their adult body often has four irregular light stripes and black blotches on their back. Their backs can be all brown or all gray. Their abdomens are white. A juvenile specimen I saw [illustrated here] was all green.

Three species of Spea are found in California: hammondii has the greatest geographic range as it occurs throughout California, as well as in northwest Baja California, Mexico. Another species occurs only in northeastern California (east of the Sierra Mountains) and another species occurs only in southeastern California.

                                          A

                                           B

A western spadefoot toad [A and B, two views of adults, both about 2 inches long; and C, view of a juvenile, about ¾ of an inch long] alongside a small creek, in the Transverse Ranges just north of San Fernando Valley, northern Los Angeles County, southern California. I did not measure exact dimensions because I did not want to disturb the animals in any way.

“A HORSE IS A HORSE, OF COURSE,” UNLESS IT IS A SEAHORSE

Seahorses are ray-finned fishes. They weight 7 ounces to 1 pound. The largest ones are up to 35 cm long.  They have a horse-like head, with elongate noses, and curled tails that are prehensile (= they have the ability to hold onto objects). Their bodies are covered with consecutive rings of interlocking bony plates. They also have tubular snouts and a small toothless mouth. They eat by suction. They no have stomach. The color of seashores can be brown to black, but they can have yellowish, reddish purple, or greenish patches. Seahorses have a ravenous appetite. Their eyes can move independently. During reproduction, the males carry the babies.  

Seahorses live one to five years in captivity. They can make good pets, but they have to have the right environment (e.g., their tanks holding at least 40 gallons of seawater). 

There are about living known genera and 225 species of seahorses. Their classification is as follows:

Phylum Chordata

Class Actinopterygii

Order Syngnathiformes

Family Syngathidae 

Genus Hippocampus (the word means horse). There are about 50 genera, and the most common one is Hippocampus. 

Seahorses branched most likely from “pipe fish," which have long and narrow bodies.” 

The earliest known fossil record of seahorses is middle Miocene (13 million years ago), in Slovenia, Europe (Zalohar et al., 2009). The skeletons are well preserved and look just like a modern seashore. There is no doubt that they are seashorses.

Three views (left, right, and front) of the skeleton of a typical Hippocampus seashorse, length 55mm (2.5 inches), width 10 mm (1.25 inches), and thickness 6 mm (1/8 inch wide). The skin of this specimen is not preserved, therefore, identification as to species was not possible.

The “weedy seahorse” or “leafy sea dragon.” (image modified from a picture in the “Eyewitness Books” Fish (p. 23). Specimens like the one illustrated here can be up to 12 inches (30 cm) in length.

Seashorses live mainly in warm waters in the Indian Ocean, Pacific Ocean (especially southern Australia) and New Zealand, and also in the Caribbean Sea. They like to live in areas where sea weeds are abundant, thereby allowing them to hide from predators.

REFERENCES CITED

Eyewitness Books (Fish), 1990. Alfred A. Knopf, New York, 64 pp.

Zalohar et al. 2009. Two new species of seahorses (Syngnathidae, Hippocampus) from the middle Miocene Tunjice Hills, Slovenia. Annales de Paleontolgie 95:21-26. 

Wikipedia. 2024.

TWO EXAMPLES OF SEA SLUGS (NUDIBRANCHS = “SEA HARES”)

Phylum Mollusca

Class Gastropoda

Order Nudibranchia

Family Tethydidae

Genus Tethys Linnaeus, 1767

Species fimbria

This group of gastropods is also called nudibranchs because they lack a hard shell. They are among the most unusual looking marine gastropods in the world! Their head is covered by a hood, and the upper part of their body has projecting external gills that can be brightly colored.

Tethys, which is one of the two living genera of this family, consists of three living species. One unforgettable example is Tethys fimbria, which lives today in the temperate waters of the Mediterranean Sea, as well as along the east coast of the Atlantic Ocean; from Portugal to the Gulf of Guinea (in western Africa). This animal crawls around on sandy and muddy bottoms, in relatively deep waters (i.e., below maximum diving depth for collectors using compressed air). But this gastropod migrates to shallower waters to spawn. It prefers to crawls around on the ocean bottom, but, if disturbed, it can swim. Tethys fimbria can grow up to 30 cm (12 in.) in length.

Figure 1. Sketch of an adult specimen of T. fimbria. Image is derived and modified from a Wikipedia image. I highly recommend that you go to Wikipedia to see amazingly beautiful images of this animal!

_________________________________________

Family Aplysiidae

Genus Aplysia

Species californica (Cooper, 1863)

This species of nudibranch is referred to as the “California Brown Sea Hare.” Adult specimens can be up to 40 cm long (16 inches) (Morris et al., 1980, p. 313) and weighing several kilograms; making it the largest known gastropod in the world. Juvenile specimens have no spots. This species is found all along the California coast, as well as that of Baja California and western Mexico (Wikipedia, 2024).

Figure 2. Sketch of an adult specimen of A. californica. Image is derived and modified from Morris et al. (1980, “page” P97 pertaining to the illustrations but not to the main text of their work, fig. 14.8a).     

Figures 3 and 4. An adult specimen, estimated 15 cm long (6 inches) of Aplysia californica in a southern California tide pool at Abalone Cove, Palos Verdes Peninsula, Los Angeles County. Images taken by Cathy Groves (affiliated with the Natural History Museum of Los Angeles County) and kindly provided by Lindsey T. Groves, Collection Manager of Mollusks, Natural History Museum of Los Angeles County, California. 

References Consulted

Linnaus, C. 1767. Systema Naturae, v. 1, 10^th edition. British Museum of Natural History, Regnum Animalae.

Morris, R.H., D.P. Abbott, and E.C. Haderlie. 1980. Stanford University Press, Stanford, California, total 690 pp., including a separate section of only photographs, numbered P1-P200.

Wikipedia, 2004

CONE-SHELLED GASTROPODS: A LONG-OVERDUE CLASSIFICATION UPGRADE

Cone shells are extremely popular with collectors because of their striking color patterns. Many have color patterns and shapes, however,  can closely resemble other similar cone shells. Therein lies “built in” confusion.

During the past two centuries, the genera and species of these shells have been being greatly overnamed! As of 2009, more than 3,200 “so-called” species, and supposedly, unique 115 genera have been named (Puillandre et al., 2015). As a result of having so many available names, many of which are unwarranted, identification of modern-cone shells as to their respective genus and/or species has been a daunting task.

Puillandre et al (2015), based on molecular studies, suggested that all these cone snail shells can be classified as a single family that is comprised of only four genera! The type species of genus Conus is one of these four genera, and it is illustrated and discussed here; [note: 85% of all cones shells are now classified as belonging to genus Conus]. 

The officially accepted type species [i.e., the species that defines this genus] of Conus is Conus marmoreus Linne, 1758 (by subsequent designation), which is shown below. It has a history of overnaming (over 100 synonym names). Like all cone gastropods, it is a predatory snail that is venomous. It lives in tropical waters in the Indian Ocean, in the western part of the Pacific Ocean (e.g., Fiji Island and the Marshall Islands), and also off Australia (e.g., Northern Territory and Queensland).

Conus marmoreus 7.5 cm height [= 3 inches], two views: apertural, followed by the abapertural view of the type species of Conus; Indo-Pacific.

The shell of C. marmoreus has a zig-zag, strikingly beautiful, reticulated color pattern consisting of spirally arranged, zig-zag rows of so-called white “tents” (triangular-shaped patches) on a black background.  The “tents” can be somewhat variable in size. The spire of this shell is lowly angled and nodular-looking. The shell is rarely orange in color. The interior of the aperture is usually white but, rarely, light pink. It is very important to remember, that cone shells, like other seashells, can have variation in their color pattern.

Classification of Conus marmoreus:

Phylum Mollusca

Class Gastropoda

Order Neogastropoda

Family Condo

Genus Conus Linnaeus, 1758 

Species marmoeus Linnaeus, 1758

The geologic time range of Conus is middle Eocene (including its fossil record in California) to present day (see Groves and Squires, 2020). Cone shells (fossil and modern-day) are usually found in warm tropical seas. Only a few species are adapted to cooler waters.

Cone shells live in intertidal to deeper depths. They commonly live on coral reefs, but can live in sand or rocks. The larger cone shells can grow up to 23 cm (9 inches) in length. A periostracum (an organic, paper-thin layer) can cover the color pattern in some species.

References Consulted:

Groves, L.T. and R.L. Squires. 2020. Checklist of California Paleogene-Neogene marine Mollusca since Keen and Bentson (1944). PaleoBios 37(1). [pdf readily available online for free].

Puillander, N., T.F. Duda, C. Meyer, B.M. Olivera, and P. Bouchet. 2015. One, four or 100 genera? A new classification of the cone snails. Journal of Molluscan Studies 81:1–23. [pdf readily available online for free].