Wednesday, March 6, 2024

THE BLUE CORAL SNAKE


While researching my last post about “Blue Coral,” I came across the topic “Blue Coral Snake.” The latter has nothing to do with "Blue Coral," but this snake does belong to the family that includes the strikingly banded and venomous "coral snakes" that live around and in coral reefs. The Blue Coral Snake, which lives in jungles, has electric blue stripes and a neon-red head. Its slender body, which can be up to 5 feet long, is blue/black with cobalt blue scales. Its tail and belly can be orange. All of this vibrant coloration serves as a warning to predators.



The "Blue Coral Snake."

The Latinized name of this snake is Calliophis bivirgatus. It lives in dense rainforests at 300 to 3,600 feet elevation, in southeast Asia (Malaysia, Burma, Thailand, Indonesia, and other neighboring regions). This snake is venomous, and its venom is extremely potent. It can cause paralysis and respiratory failure. Calliophis bivirgatus belongs to the family Elapidae, which includes cobras and sea snakes. The blue coral snake can prey on young king cobras. 


The blue coral snake is timid and primarily nocturnal. It eats other snakes, as well as small lizards. Its has specialized teeth that curve backward, thereby holding onto its prey. It venom glands, which are located behind its eyes, are the biggest venom glands in the world. Its venom can be fatal to humans, and there is currently no anti-venom. This venom is like that of most other deadly snakes, it that it  can cause its prey to instantly freeze with muscle spasms (cramps). Its venom is similar to that of some spiders and scorpions, as well as to cone snails (e.g., Conus geographus---see my April 22, 2019 blog post on “Cone shells Past and Present.”


This snake has a defensive position that mimics cobras, i.e. its flattens the neck and raises its forebody off the ground. Females are larger than the male. This snake can live up to 20 years.


References Consulted


facts.net/nauture/animals


businessinsider.com/blue-coral-snake-venom

 

Monday, March 4, 2024

“THE BLUE CORAL”

This animal, known scientifically as Heliopora coerulea (Pallas, 1766), is an extant octocoral with a massive skeleton (up to a meter in diameter that can be columnar, plate-like, or branched). The blue color of its skeleton is often obscured by the brownish to gray-brown color of its living tissues. The skeleton itself contains iron salts that produce its unique blue color. Furthermore, the skeleton consists of fibrocrystalline aragonite (a type of calcium carbonate). It is a hermatypic zooanthellaete species with polyps in the skeleton. Each polyp has eight tentacles.


Heliopora colonies are variable in their shape, ranging from branching forms (with blunt ends) to encrusting forms.


Heliopora coerulea: 8.5 inches [21 cm] wide and 6 inches [15.2 cm tall], from the Philippines. 


Close-up of a part of the specimen of H. coerulea shown above.


The surface of the skeleton is smooth and perforated by cylindrical pits of two sizes: 1) widely-spaced “tiny black holes” up to 0.25 mm diameter and encircled by a stellate margin and 2) much smaller tubular-shaped openings used by the autozooids (part of the internal canal system that contains the zooanthellae = the symbiotic algae).


An even more close-up of the same specimen of H. coerulea shown above. Notice the two different sizes of openings in the skeleton: the autozooids = black holes (each one up to 0.25 mm diameter and encircled by a stellate margin) and the much smaller (near microscopic size) tubular openings that, according to Wood (1983) enclosed extensions of the internal-canal system that contained the zooxanthellae.


Heliopora coerulea is a species that can tolerate thermal changes. It has a fossil record since the Cretaceous. The morphology of this octocoral has changed little since then.


The geographic occurrence today of H. coerulea is confined to the tropics: Indian Ocean and western Pacific Ocean, including the Japan and the Great Barrier Reef of Australia. It lives nearshore on reefs, in depths below two meters. It is a vulnerable species.


Its classification is: 

Phylum Cnidaria

Subphylum Anthozoa

*Class Octocorallia (lack true septa)

Order Helioporacea (includes only one genus: Heliopora)

Family Helioporidae

Genus Heliopora

Species H. coerulea

**Species H. hiberniana


In addition to the “Blue Coral,” octocorals include soft corals (such as Tubipora = the red-colored organ-pipe coral), sea pens, and gorgonians (sea fans and sea whips). There are about 3,000 known species of octocorals. They have colonial polyps with eight-fold symmetry (note: true corals have hexa-radial symmetry).


Zoe et al. (2018) reported a new species of living Heliopora, namely H. hiberniana, from offshore areas in north Western Australia. It differs from the “Blue Coral” by having a white skeleton, more slender branches, and some differences in skeletal morphology.

References Cited or Used:


en.wikipedia.org/wiki/Blue_coral


gbif.org/occurrence/1039258522

   [this online site is via the Invertebrate Zoology Division, Yale Peabody Museum]


Wood, E. M. 1983. Corals of the world. T.F.H. Publications. Neptune City, New Jersey, 256 pp.


Zoe, T.R., and seven others. 2018. Integrated evidence reveals a new species in the ancient blue coral genus Heliopora (Octocorallia). Scientific Reports 8, article no. 15875. 

Monday, February 26, 2024

DINOSAURS IN ANTARCTICA

Six genera are known: two are Early Jurassic age and four are Late Cretaceous age (Campanian Stage/Maastrichtian Stage). These genera are unique to Antarctica, but they are generally closely related to either South American dinosaurs.

When dinosaurs lived in Antarctica, the continent was ice free. During warm Early Jurassic time, all the continents on Earth were part of the single large continent called Pangea, which existed from the Late Paleozoic to the Triassic/early Jurassic time. Then the northern part of Pangea (Laurasia) separated and the central Atlantic Ocean simultaneously began to open up. The southern part of Pangea (Gondwana), which included South America, Africa, Arabia, Madagascar, India, New Zealand, Antarctica, and Australia, eventually underwent its own breakup, which occurred in stages. It started with Africa and South America separating from India, Antarctica, and Australia. During Cenozoic Paleogene time (66 to 23 mya), Antarctica became a separate continent. Its climate was mild until 34 mya (= end of the Eocene and beginning of the Oligocene), when continental glaciers began to accumulate in Antarctica.


                                        Figure 1. Pangea 


Figure 2. Breakup of Pangea, with Gondwana = all the
 southern continents.


By Middle Cretaceous times, dinosaurs in Antarctica were geographically somewhat isolated, but close connection between Antarctica and Australia still existed.


EARLY JURASSIC DINOSAURS


The two middle Early Jurassic (Pliensbachian Stage) [199–183 million years ago] dinosaurs found in Antarctica are the theropod Cryolophosaurus and the sauropod Glacialisaurus.

Their remains are both found at the same site in the Hanson Formation in the central part of the Transantartica Mountains that “divide” western from eastern Antarctica. This mountain chain was an active volcanic rift-system area.


Google-Earth image showing the location of the Hanson Formation in the Transantarctica Mountains.

 

Cryolophosaurus elliotti is based on a single specimen. It is the only theropod found so far in Antarctica. This dinosaur, which was an “apex predator” was 8 feet in height at the hips, 21 to 26 feet long, and it is estimated to have weighed 1000 pounds. It has an unusual-looking pompadour spanning its head from side to side. This dinosaur had primitive needle-like feathers.


Glacialisaurus hammeri is based on two specimens. This early sauropodomorph dinosaur was 20-25 feet long, and is estimated to have weighed approximately 5 tons. It had leaf-shaped teeth.


LATE CRETACEOUS DINOSAURS


Two of the four Late Cretaceous dinosaurs found in Antarctica are of Late Cretaceous age and have been reported as of Campanian Stage-age (79-77 mya). The other two dinosaurs have been reported as of Maastrichtian Stage-age (68 mya) age. All of their remains, however, are found at the same site in the Snow Hill Formation on Seymour Island, which is located just south of South America. These Snow Hill Formation dinosaurs are closely related to South American dinosaurs. 


Google-Earth image of the Late Cretaceous Snow Hill Formation dinosaur locale on Seymour Island.


Antarctopelta oliveroi is based on a single specimen of reportedly upper Campanian age. This ankylosaur was a herbivore with armor plates. This dinosaur is estimated as having been 13 feet (4 m) long.



Trinisaura is based on a single specimen of upper Campanian age. This ornithopod was 2.5 feet tall and 5 feet in length. 


Morrosaurus is based on a single specimen. This ornithopod was a herbivore elasmarian genus. Its geologic age has been reported as of Maastrichtian Stage (approximately 68 mya) of the Late Cretaceous  Period (approximately 68 mya). 




Imperobator is a paravian theropod (“an early bird”) that has been reportedly as of Maastrictian age. This dinosaur lacked an  enlarged sickle claw.


The biodiversity of Antarctican dinosaurs is very low, but this is to be expected because the continent is currently covered in glacial ice and the climate is not conducive to prospecting for fossils.


References Consulted:


wikipedia.org



Tuesday, February 20, 2024

MOUNT EREBUS, ANTARCTICA: THE WORLD’S SOUTHERMOST ACTIVE VOLCANO

This volcano is on Ross Island, near McMurdo Station (USA) and Scott Base (New Zealand). [Note: McMurdo Station sits on the mainland of the Antarctica continent]. Mount Erebus is the southernmost active volcano on Earth (at approximately 77.5°S, 167.1º E) and is one of the only few volcanoes that is consistently active. Ross Island also has three other volcanoes, but they are inactive. Mount Erebus was discovered in 1841 by the polar explorer Sir James Clark Ross. In Greek mythology, the father of Erebus was Chaos, and Erebus’ mother was Gaia (or Earth). Erebus was made of darkness, and he filled the corners of the world with darkness; thus, Erebus means a “dark region.”

Figure 1. Antarctica in relation to South America and Africa (a Google Earth image), and the location of Mount Erebus. 



Figure 2. Location of Mount Erebus on Ross Island.


Mount Erebus has been active for 1.3 million years. It is a polygenetic stratovolcano composed of anorthosite-porhyrite and tephrite phonolite. The bottom half is a shield volcano, whereas the upper half, whose slope dips approximately 30°, is a strato-volcano, with a lava lake in its inner summit crater. This lava (magma) lake is permanent, and there is continuous degassing (Wikipedia). Also, it spews out, on the average, 80 grams of gold a day, all of it is dissolved in the sulfurous volcanic gases (atlasobuscua.com/places/mt-erebus).



Figure 3. Side view of Mount Erebus, as seen from a tourist ship on the Ross Sea. You can readily see the dual-aspect of the shape of this volcano. 


Figure 4. Caldera (housing a lava lake) at the top of Mount Erebus. There are two inactive calderas on the flank of the active caldera.



Figure 5. NASA satellite image showing the glowing, active lava lake in the active caldera at the top of Mount Erebus.


There are fumarolic ice towers, up to 60 feet high, associated with this volcano, and they form around escaping gases on the surface of the volcano.

Figure 6. A fumarolic ice tower (a public domain image taken in 2010 by Peter Rejeck, National Science Foundation, see photolibrary, usap.gov). The original of this image is on the public domain website: atlasobscura.com/places/mt-erebus).


Additionally, there are dark ice caves associated with this volcano. They have relatively warm temperatures (a constant of 32°, making them likely to be home to extremeophile organisms (e.g., moss, algae, some arthropods, and some nematodes can live in these caves) (Wikipedia).


Websites Consulted


atlasobuscua.com/places/mt-erebus


coolantarctica.com


en.Wikipedia.org


photolibrary.usap.gov


Wednesday, February 14, 2024

THE TETHYAN CURRENT CONNECTION

The Late Cretaceous, Paleocene, and Eocene (see the time diagram shown below) world oceans were influenced by a warm  equatorial (tropical) current known as the Tethys Current, which flowed westward from the Tethys Sea in Asia and Western Europe and continued westward into southern Mexico and Central America. This current dispersed the larvae of marine mollusks and other biota into the west coast of North America, as far north as Washington. This dispersal coincided mainly with the early Eocene, the warmest time of the last 65 million years of Earth history.


The position of the Tethys Current is shown below. There was an open

seaway connection between the Atlantic and the Pacific oceans in the area now known as Central America and South America. Shallow-marine mollusks found in Eocene rocks show very strong affinities to their counterparts in the Gulf Coast of the United States and in Western Europe (i.e., southern England, France, and Italy). 



Since the 1920’s, in the Gulf Coast, and the 1930’s in California, invertebrate paleontologists studying large foraminifera, corals, mollusks, crabs, and echinoderms, have noted very similar looking species in these regions versus that of southern England and France. During the last 40 years, I have focused my own research largely on establishing the details of this influx of Western European thermophilic (warm water) genera and their related species into the west coast of the United States, especially into southern California.


By the means of detailed geologic mapping, extensive collecting, and analyses of the collected fossils, I and my students have been able to determine that the most extensive influx of mollusks from the Old World was during the warmest time of the Eocene; namely, the early Eocene [especially during an interval of geologic time known as the “Capay Stage,”] about 45 million years ago. This stage coincided with the Early Eocene Climate Optimum (= EECO). Subsequent tectonic activity displaced the rocks containing these fossils northward several hundred miles and also rotated some of the rocks nearly 90 degrees clockwise. This tectonic displacement was not recognized (by paleomagnetic studies) until the 1990’s.


Among the most famous of the mollusks that were introduced into are the gastropods Velates, Campanile, Gisortia, and Clavilithes. There are also many others, but these four genera are representative. At the end this post, I figure and discuss these genera. 


                                      


Reference:

Savazzi, E. 1992. Shell construction, life habits and evolution in the gastropod Velates. Palaeogeography, Palaeoclimatology, Palaeoecology 99:349-360. Costs $$ to view online.



Comparison Between Western Europe and California Eocene                      Gastropod Species: 


Velates perversus Paris Basin, France, two views: side and aperture.



The name “Velates” is derived most likely from the word “velum,” which is a veil or membrane covering; sort of like a length of cloth attached to a hat, thus covering the neck and shoulders (like the extension of the helmet of the character "Darth Vader" in the “Starwars” movies). Adult Velates shells normally a lateral (sideways) sloping extension.


Velates belongs to family Neritidae, which most collectors refer to as nerites, whose living members (several hundred species) are small with brightly colored shells that can be found in trees, springs, rivers, swamps, marshes, and brackish water. Most species are found, however, in shallow-marine waters, especially along intertidal coastlines in tropical seas. 


Velates ranges in time from, possibly Late Cretaceous, but with certainty from Paleocene to Eocene in Europe, Africa, Asia, North America, and the Caribbean region. Velates is peculiar for nerites: it has the largest shells of any nerite (fossil or living), the aperture occupies about one-third of the base of the shell, with the rest consisting of a thick callus.


Their largest shells reached about 150 mm in diameter; making Velates the largest neritid. Its shell is unusual for a nerite because of its considerable thickness, especially on its ventral surface, where a broad thick callus (shell buildup) creates a very wide, smooth surface (pad). Whereas nearly all nerites are free to crawl around, it appears that Velates was rather comfortable in settling partially into the sediment substrate (i.e., the basal callus pad created an “anchor” of sorts). Thus, Velates might have been a partial burrower in soft-bottomed sediments. The thick callus would could have served as an “anchor.” Other evidence to support a burrowing lifestyle is that its outer surface of the shell is smooth and shiny and never show attached epibionts (unless they occurred post-mortem). There are only a few nerites that live today as infaunal soft-bottom dwellers, but these nerites are small in size.


 The Velates specimens that I and my students were fortunate to find and collect were present only in transgressive  (deepening upsection) facies in shallow-marine water environments near the bases of formations. They are not scattered throughout a formation which has different environments of deposition.



Gisorta tuberculosaFrance, left image, apertural view.
Gisortia clarki, California, right image, apertural view.


Gisortia tuberculosa, France, left image, dorsal view.
Gisortia clarki from California, left imagedorsal view.
The size of this California specimen is length 12 cm. 

The genus Gisortia belongs to family Cypraeidae (i.e., popularly known as the cowries). The global geological time range of Gisortia is Late Cretaceous (Maastrichtian) to late Eocene, but on the west coast of North America this genus occurs only in lower Eocene (“Capay Stage”) strata in southern Baja California, Mexico and in southern and central California. Gisortia is a large-sized gastropod shallow-marine gastropod.




Clavilithes longaevus, France, left image: apertural view, 
right image: dorsal view.


Clavilithes tabulatus from California. Left image: apertural view, 
right image: dorsal view.

Clavilithes lived from Paleocene to Pliocene, with various species found in Africa, Asia, Europe (especially southernmost England and also the Paris Basin, France), North America, and South America. In California, it is restricted to the early Eocene and to the lower part of the middle Eocene. It is a very distinctive genus, with tabulate shells ± fine spiral ribs. Individuals can reach up to 85 mm in height and 35 mm in width.



Clavilithes giganteum Lamarck, left image, an incomplete specimen from middle Eocene deposits, Paris Basin, France
right image: Campanile dilloni from southern California: dorsal view, height 15.5 cm.

Campanile has a geologic range from Late Cretaceous (Maastrichtian) to recent. Today, it occurs only in the Perth area of southwestern Australia. On the Pacific coast of North America, it is found in Paleocene an Eocene deposits, in California and Baja California Sur, Mexico.



Sunday, February 11, 2024

THE STRANGE OARFISH


Classification of the oarfish:

Phylum Chordata

Class Actinopterygii

Order Lampriformes

Family Regalecidae

Genus Regalecus

(Two) Species: glesne Ascaniusm 1772 and russelii (Cuvier, 1816)


Both species are circum-global, but only R. russelii has been found in California (Feeney and Lea, 2018).


The living oarfish is a ray-finned fish with a ribbon-like shape that can be up to 36 feet long (11 m). It has a circum-global distribution, except for polar regions. It is most commonly found in the tropics to middle latitudes. It lives at depths of 3,200 feet (1,000 m) but can occur in shallower water (nearshore to 200 m depths). It is rarely been seen in the vicinity of beaches, unless it has been washed up. In such cases, even in southern California, it creates great attention. Typically, in such cases, pictures will be taken with 15 or 20 people holding up a dead oarfish. 


This actual specimen of an oarfish (Regalecus sp.) is on display in an exhibit at the Natural History Museum of Los Angeles County (LACM). This specimen is 14.5 feet long. It was alive when it swam into Big Fisherman Cove at Catalina Island in 2006. Researchers photographed it as they swam aside it, before it died of natural causes. Image courtesy of Lindsey T. Groves, Collections Manager of Malacology at LACM. 


My sketch of a living oarfish.


In forklore, oarfish have been associated with “sea serpents” and forbearers of doomsday calamities (e.g., earthquakes and other catastrophic changes).


The oarfish body is narrow laterally, with a dorsal fin (typically reddish) along the entire length. It swims, in an undulating manner, by means of its dorsal fin, but it and can also swim in a vertical position. Its head is small with no teeth (it swallows small-sized marine crustaceans, called krill). Also the oarfish has no swim bladder. 


It has a small head with no teeth, but it eats krill. 


The ancestor of the extant giant oarfish might have been stickleback fish, which possibly date back to the Early Cretaceous (early Cenomanian Stage) in Italy (see (Sorbini, 1966). It is also interesting to note that stickleback fish today are confined to the Northern Hemisphere where they can live in oceans, brackish, or fresh water.


References Cited and/or used:


australian.museum


Feeney, R.F. and R.N. Lea. 2018. California records of the oarfish, Regalecus russelii (Cuvier, 1816) (Actinopterygii: Regalecidae). Bulletin of Southern California Academy of Sciences 117(3):169–179. (pdf available online, for free).


Sorbini, L. 1996. New superfamily and three new families of tetraodoniform fishes from the Upper Cretaceous: the earliest and most morphologically primitive Pectognatus. Smithsonian Contributions to Paleontology 82:1–59. (pdf available online, for free).


en.Wikipedia.org