SOME WILDFLOWERS ENCOUNTERED WHILE PROSPECTING FOR FOSSIL MOLLUSKS

It is always a pleasure when I encounter some beautiful wildflowers while prospecting for fossils. While doing field work in northern Los Angeles County in southern California, I have often hiked through localized areas where wildflowers are in bloom during late spring to early summer. One such example is on the north flank of the overturned (north-vergent) Pico Anticline of the Santa Susana Mountains. This anticline, which trends northwestwardly for approximately 9 miles (15 km) was an oil-producing structure between the 1840’s and the 1940’s.

Geologic cross section of the Pico Anticline, with the red spot indicating the patches of poppy/lunpine flowers (see below for images of the flowers). They grow on soil associated with a transitional sedimentary sequence consisting of interbedded mudstone/siltstone and fine sandstone within the lower Pliocene Miocene Towsley Formation. This area where the wildflowers are concentrated is on southeast-dipping beds that are nearly recumbent (overturned). It is likely the combination of a favorable elevation for rainfall (about 1900 feet above sea level), fine-grained soil for retaining moisture, and a south-eastwardly facing slope have created ideal conditions for the localized growth of these flowers.  

THE CALIFORNIA POPPY

Family Papavaraceae [the poppy family]: about half of the 26 genera belonging this family are found in California.

Genus Eschschholzia: all of its species have bright yellow or orange flowers.

Comments: The fruit (= a capsule) is a source of heroin and morphine. The deep tap   roots of this plant allows for the plants to persist for several seasons. This is California’s state flower (decreed in 1903).

 Poppy field with some scattered lupines (purple).

Another poppy field with more lupines.   

LUPINE

Family Gabaceae [the Pea family]. Second to sunflowers family, this is one of the largest families of plants.

Genus Lupinus: there are over 82 species found in California. The flowers range in color from blue to purple to white.

Comments: The genus name means “wolf,” because these plants rob the soil of its nutrients. Lupine is a benefical plant because it adds nitrogen to the soil through its root nodules. This plants, however, can also produce dangerous alkaloids contained primarily in their fruits.

Slope covered with lupines.

STICKY-LEAF MONKEY FLOWER

Family Scrophulariaceas [the figwort family].

Genus Mimulus: there are 150–175 species in California.

Comments: This wildflower is extremely widespread in North America. The herbage of this plants is “sticky,” hence its name.

An example of the sticky-leaf money flower shrub in the Pico

Anticline area.

MUGWART

Family Asteracea [the daisy family]

Genus Artemisia

Comments: This plant is widespread in the world, and there are 13 species. In southern California, it is found at elevations less than 6,000 feet. During the summer, this plant has small clusters of red/brown flowers with white bases (Wikipedia, 2024; diagram insert), but I have never seen any of them (I usually did my field in the Spring). Mugwart is an aromatic plant with a strong sage odor. The tops of its leaves are green, but the bottoms are gray.

Mugwart plants in the Pico Anticline area. The view about 1 foot in width. 

 A sketch (based on a Wikipedia image) showing mugwart flowers (red tops and white bases) (each flower about 1 inch long).

POISON OAK

Family Anacadiaceae [the sumac family]

Genus Toxicodendron

Comments: Although most authors do not classify poison oak as a wildflower, this plant does produce white flowers in the spring. It is a very common shrub in southern California. I include pictures of it here because some students that have accompanied me in the field had no idea what this plant even looks like. They soon learn if they get blisters! 

Contact with poison oak should be avoided at all costs, because it toxic plat can produce very itchy, red-colored sores on one's skin that can last for several days!

Poison oak (Toxicodenron diversilobum) occurs in California, Baja California, Nevada, Oregon, Washington, and British Columbia (Wikipedia).

Despite its name, it is not closely related to oaks, nor is it a true tree. Poison oak prefers to live on north-facing slopes. Its leaves are scalloped. In the spring, their leaves are green, but they turn red in late July to October.

Poison oak shrub, Pico Anticline area in July.

Close-up of poison oak leaves in the vicinity of the Pico Anticline in October. The tops of poison-oak leaves usually have a somewhat waxy appearance.  

References:

Belzer, T.J. 1984. Roadside plants of southern California. Mountain Press Publishing Company, Missoula. 158 pp.

en.wikipedia.org 2004.

SPECTACULAR COLOR VARIATION IN THE GASTROPOD VEXILLUM

Many year ago, I purchased two gastropod shells from the a shell store [now now closed] known as the “Tidepool Gallery” in Malibu, southern California. These shells, which have vivid color bands, are shown below. One has brown, black, and white spiral bands. The other shell has orange, white, and a few black spiral bands. It wasn't until until recently that I carefully studied these shells and decided to write a blog post about them. I immediately had problems in trying to identify them. I knew that they belonged to family Costellariidae and to genus Vexillum, but I was stumped when it came to identifying them as to species. Their colors are different than published images of this species, but colors in shells can be highly variable. Their morphology however is nearly the same, so I suspected that they belong to the same species. Consulting WoRMS (2023) confirmed my identification that both color variants are the same species; namely, Vexillum colosopulus (Jean Cate, 1961).

This gastropod belongs to family Costellariidae (= the ribbed miters). There are many species of this genus, and its high-spired multi-colored shells can show considerable variation in their color, with white, gray, orange, dark brown, and black spiral stripes. Cate’s species lives in tropical shallow-marine waters of the Western Pacific Ocean and Indian Ocean. This gastropod is predatory and, like other costellariids, it secretes toxins to immobilize and kill its prey.

Two views: apertural and abapertural, height 6.55 cm, width 1.5. cm) of Vexillum colosopulus (J.M. Cate, 1961), from Balbac, in the Philippines.

Two views: apertural and abapertural, height 5 cm, width 1.3 cm, of a different-colored variety of Vexillum colosopulus (J.M. Cate. 1961), West Pacific.

Cited References

Cate, Jean M. 1961. A discussion of Vexillum regina (Sowerby, 1825) and related species, with description of a new subspecies. The Veliger 4(9):76–85. [pdf available for free at biodiversitylibrary.org]

WoRMS, 2023. http://marinespecies.org

THE CASSOWARY: AN UNUSUAL ANCIENT BIRD

The cassowary is an extant flightless bird belonging to an evolutionary group called “ratites,” which do not have a keel on their sterum (i.e., on their-plate); thus, they cannot fly. Other living ratites are the dwarf cassowary, emu, ostrich, rhea, rhea, and the kiwi. The elephant bird is an extinct ratite.

DISTRIBUTION The cassowary originated in Australia, but, during the Pleistocene Ice Age, it spread northward from Australia for about 90 miles, via a land bridge, into the world’s second largest island, comprised of two parts: New Guinea [now regarded as part of Indonesia] and Paupau New Guinea [PNG] [an independent nation west of Guinea] (see figure below). Ratites are present also in areas immediately adjacent to New Guinea; these areas are New Britain (just northeast of PNG), the Aru Islands, and Yapen [= Yappen Island].

Google Earth Satellite Image (2023) showing the geographic relationship of New Guinea/Papau New Guinea region versus Australia and the equator.

Examples of other animals that spread northward via this land bridge are kangaroos (some of which evolved into the “tree kangaroo”---see one of my recent posts).

The tectonic history of the Indonesian/PNG region is complex. For an overview see Baldwin et al. (2012).

The preferred habitat of most cassowaries is tropical rainforests, mainly in lowland areas, including any tidal flats found in these areas. In the New Guinea and PNG areas, cassowaries can also live at higher altitudes on the sides of the many volcanoes; some of which are active. These volcanoes, which occur in a linear fashion along the middle part of  New Guinea and PNG, can reach elevations up to 16,024 feet and be associated with their own localized glaciers. This arc of volcanoes (caused by a nearby tectonic trench where subduction is taking place) is part of the so-called active “ring of fire” that characterizes the western Pacific region. The entire Indonesia and PNG area has more than any other region in the world. It is notable that the above-mentioned glaciers are located near 0 and 10 degrees north of the equator.

SCIENTIFIC CLASSIFICATION 

  Class Aves

  Infraclass Palaeognathae

  Order Casuariiformes

  Family Casuariidae

  Genus Casuarius, with three known extant species:

  

  1) Species causarius known as the “southern species” found only in northeast Australia,  (especially Queensland, New Guinea, and Aru Islands (just southwest of New Guinea).

  

  2) Species unappendicuatus known as the “northern species” found only in Papau, New Guinea and, sparingly, on Yapen Island (just northwest of New Guinea).

   

  3) Species bennetti known as the dwarf cassowary, found only in the Papau/ New Guinea region. This species is more closely related to the “northern species” than to the “southern species.”

note: More genetic studies are needed to help to distinguish the species of cassowaries. There might be more species recognized in the future (Naish and Perron, 2014). 

BODY FEATURES

Cassowaries, which are second only to the ostrich in size, can be up to 4 feet tall and weigh as much as 150 pounds. They are the heaviest bird in Australia and the third-largest bird in the world, behind the ostrich and the emu.

Sketch of Casuarius casuarius, the southern Cassowary. This species is known also as the "Australian cassowary" or as the two-wattled cassowary," in reference to the two red-fleshy extensions at the base of its neck). Each cassowary species has its own distinctive number of wattles (one or two “cords of loose skin hanging loosely down from the neck area). 

The feathers of the cassowary consist of stiff quills that resemble porcupines. Unlike porcupines, however, there are no bards on the ends of the cassowary quills.

The head and neck of the cassowary can have bright colors (redish, bluish, and or yellow-orange), but the variable color is not all that reliable for species identification. The rest of the body is black. Female necks have brighter coloration. Cassowary chicks have brown and creamy-white stripes, which fade to brown after six months; obtaining mature coloration requires approximately three years.

On top of its head, the cassowary has a structure (known as a casque) consisting of skin-covered keratinous material that grows with age. The function of this structure has not been established, but it has been speculated that it is used to produce low-frequency sounds (i.e., “boom” sounds used for vocalization), used as a thermal radiator, or used to crash through dense vegetation—although, in fact, they move silently through dense forests.

The morphology of a cassowary casque (source of image unknown). Each species has its own uniquely shaped casque.

The feet of the cassowary have sharp, dagger-like claws, with the innermost claw being a spike-like dagger measuring up to 12 cm (4.75 inches) long. The cassowary uses these sharp-clawed feet to kick predators and to defend themselves. This bird can jump nearly seven feet (2 m) straight up into the air! Cassowaries have been known to kill humans, especially if they threaten these birds or their chicks. Usually, like with almost all animals, if you leave them alone, the cassowary will leave you alone.

A southern cassowary in ATTACK mode! The attack can be sudden and “full of fury.” Cassowaries can be very dangerous because they are so unpredictable and so powerful.

Cassowaries can also run up to 31 mph (50 km per hour), and they are good swimmers.

DIET

Fruit (up to 240 different species, including bananas and apples) comprise 90 percent of their diet. In many cases they swallow the fruit whole, thus making them “keystone species,” as they disperse whole seeds throughout the forests.

They also eat grass shoots and grass seeds. They can also eat fungi, insects, eggs, fish, frogs, lizards, snakes, small birds, and rodents, as well as carrion.

AN ENDANGERED ANIMAL

Cassowaries are a threated species mainly because of habitat destruction by humans [sounds familiar, eh?]. In fact, cassowaries are a species “living on the edge.” 

ANCESTRY

On the basis of modern research, it is now known that birds (including ratites) are closely related to dinosaurs. Furthermore, it is now known that based on the presence of a casque on their head, having feet with three sharp-nailed toes, and similar respiratory systems, cassowaries are more similar to dinosaurs than other birds. But, determining just how close they are related and their intricate evolutionary pathways, needs more research.

REFERENCES CONSULTED

Baldwin, S.L. et al. 2012. Tectonics of the New Guinea region. Annual Review of Earth and Planetary Sciences, v. 40, pp. 495-520. DOI: 1146/annurev-earth-040809-152540

EarthxTV [in association with the Animal Planet]; an episode called “The Ultimate Surviors.”

McInerey, P. L. et al. 2019. BMC Evolutiony Biology. DOI: 10.1186/s12S62-019-01544-7

Nasih, D. and R. Perron. 2014. Structure and function of the cassowary’s casque and its implications for cassory history, biology, and evolution. Historical Biology 

   http://dx.org/10.1080/0891263.2014.985669 (free pdf, with excellent photos and drawings)

en.Wikipedia.org

 

EXAMPLES OF SOME OTHER IRREGULAR ECHINOIDS

This blog post is about oligopygoids, cassiduloids, and spatangoids, all of which are irregular echinoids; thus also classified with sand dollars. For examples and details concerning just sand dollars, please see my blog that immediately precedes this present blog.

Echinoids range from the Paleozoic (starting in the Ordovician Period) to modern day. As adults, they crawl about on the ocean floor. Like all the other invertebrates, echinoids underwent significant changes in their modes of life during Mesozoic time because of increasing predation by predators.

Figure 1: Life zones of regular echinoids versus geologic time. 

Haimea bajasurensis Squires and Demetrion, 1994

                              (two views: top and left side)

     Order Oligopygoida

     Family Oligopygidae

Range: Lower Eocene, Baja California Sur, Mexico. THIS IS A FOSSIL SPECIES. It is both the earliest and the westernmost oligopygoid, and the first occurrence of Haimea in North America.

This is a fossil species. Baja California Sur, Mexico.

Habitat: Shallow-marine.

Source of Information: Squires and Demetrion, 1994. 

Dimensions of Figured Specimen: Length 18 mm, width 15.7 mm.

Figure 1a: top view.

Figure 1b: side view.

                    Calilampus californiensis Squires, 1995

                            (two views: top and left side)

     Order Cassiduloida

     Family Cassidulidae

Range: Lower Eocene, Baja California Sur, Mexico. THIS IS A FOSSIL SPECIES.

Habitat: Shallow-marine.

Source of Information: Squires and Demetrion. 1995. 

Dimensions of Figured Specimen: Length 3.5 cm, width 2.9 cm.

Lovenia cordiformis A. Agassiz, 1872

(two views: top and bottom)

     Order Spatangoida [The heart-shaped echinoids].

     Family Loveniidae

Range: Santa Cruz Island, southern California to Panama, Coco Islands, and the Galapagos; rare in Columbia.

Habitat: Infaunal (about 15 cm depth) in sandy sediment, in the low-intertidal zone to a depth of 200 m.

Shell: Surface is covered by long, brown hair-like spines; the shell resembles a small coconut.

Source of Information: Marine Biodiversity Records “https:/mbrbiomedicalcentral.com

Dimensions of Figured Specimen: Length 5.4 cm, width 3.6 cm.

                  Micraster cor-anguinum (Leske), a plaster cast.

           (four successive views: top, left side, bottom, posterior)

     

     Order Spatanogoida

     Family Micrasteridae

Range: THIS IS A FOSSIL SPECIES. Upper Chalk beds, Upper Cretaceous (Senonian), from Pinden, near Dartford, Kent, England. 

Fossil Locality: This genus lived from Late Cretaceous (Cenomanian) to early Eocene. It was moderately widespread, with species in Europe, North America (mainly the Gulf Coast states), Egypt, and Antarctica (rare). 

Source of Information: Wikipedia (2023). 

Dimensions of Figured Specimen: length 6 cm, width 5.3 cm.

                          Meoma ventricosa? (Lamarck, 1816)

                        (three views: top, bottom, and left side)

     

   Order Spatnagoida

   Family Brissidae

Common Names: Cake urchin and “red heart” urchin.

Range: Florida, the Bahamas, Bermuda, Jamaica, Virgin Islands, and West Indies, Caribbean, southern Mexico, northern Venezuela.

Habitat: Shallow waters. They burrow into sand at the rate of about 3 to 6 cm an hour during the day, and twice as fast during the night.

Shell: Spines blackish-red in color.

Source of Information: Wikipedia (2023).  

Dimensions of Figured Specimen: Length 135 cm, width 112.5 cm, thickness 67 cm.

                    Agassizia scrobiculata Valenciennes, 1846

               (four views: left to right--for both rows--top, 

                          bottom, left side, and posterior)

     

   Order Spantangoida

   Family Prenasteridae

Common Name:

Range: Only two known species. Upper Gulf of California, Baja California, Mexico to Peru and the Galapagos Islands.

Habitat: Largely subtidal, at depths 0 to 76m, on sandy, muddy, or rocky bottoms. 

Shell: Small, normal size 20 to 35 mm length.

Source of Information: Brusca (1980).

Dimensions of Figured Specimen: Length 35 mm, width 30 mm, thickness 26 mm.

References Cited:

Brusca, R. C. 1980. Common intertidal invertebrates of the Gulf of California. Second edition. The University of Arizona Press, Tucson, Arizona, 513 pp. 

Squires, R.L. and R.A. Demetrion. 1994. A new species of the oligolpygoid echinoid Haimea from the lower Eocene of Baja California Sur, Mexico. Journal of Paleontology 68(4):pp. 846–851, figs. 1–3.

Squires, R.L. and R.A. Demetrion. 1995. A new genus of cassiduloid echinoid from the lower Eocene of the Pacific coast of western North America and a new report of Cassidulus ellipticus Kew, 1920, from the lower Eocene of Baja California Sur, Mexico. Journal of Paleontology 69(3):509–515. 

en. Wikipedia.org