TRILOBITES FROM MOROCCO, AFRICA

Morocco has great generic diversity of Cambrian and Devonian trilobites, and some have excellent preservation. There are many commercial websites devoted to selling the vast array of specimens. Prices for some of the most spectacular specimens (especially those that are very spinose) can be very expensive! Some of the websites that I visited in preparing this post are listed at then end of my comments. The purpose of this blog post is to provide a brief overview of the types of trilobites found in Morocco.

Google-Earth satellite photo of Morocco and also the general area of the location of some of the spinose trilobites, which are mentioned lastly in this blog post.

My version of the geologic history of trilobites, including

those found in Morocco. 

Large trilobites were moderately common during the Cambrian Period in Morocco, whereas spiny trilobites were especially diverse in the Devonian Period. Throughout these geologic times, Morocco was located in the ancient supercontinent called "Gondwana." The maps are based on information found in Scotese (2021).

Dorsal view of a specimen of Aacadoparadoxides briareus?, which is a Middle Cambrian large redlichiid trilobite, about 10 inches in length. Specimens can be up to 15 inches in length. This trilobite is found in Morocco, USA (Alaska, Massachusetts, South Carolina), southeast Canada, South America, Europe, Norway, Poland, and Russia (jurassic-dreams.com).

The specimen illustrated here could be a “fake,” as they are common for this trilobite. Their shells are very thin and subject to breakage during quarrying; thus they usually require some or extensive restorative “cosmetic surgery.” It the price for a large and perfect specimen is only a few hundred dollars, it is likely that it is fake. Nevertheless, it could have great eye-appeal.

Three specimens of the Cambrian trilobite Campropallas teleoso. The largest specimen (upper right-hand corner of image) is 8.5 inches in length and 6 inches wide (image courtesy of Julia and David Denman).The exoskeleton (carapace) of this species is typically very fragile because it is so thin; thus, craftsmen in Morocco have to usually do some repair in order to restore the specimens.

Dorsal view of the exoskeleton (6 cm length and 4 cm width) and also a view of the left (“tower” eye, 0.5 cm tall and 1 cm wide) of the Devonian trilobite Coltrania? oufatensis. The elevated eye (with lenses preserved—which is common in Moroccan trilobites), allowed this animal to be able to see any predators approaching from behind.

                                                    

Dorsal and left-lateral views of the exoskeleton (6 cm length and 3 cm width) of Devonian trilobite Erbenochile? sp. Its eyes (with the lenses preserved) are elevated. Scratch marks, which were made by the tools of the preparators of Moroccan trilobites, is a “trademark” of many fossils quarried and sold from this region.

Dorsal and right-lateral views of the exoskeleton (4.2 cm length, 2.5 cm width) of a phacopid trilobite from Morocco. Its eyes are large and moderately elevated. Identification as to genus and species is difficult because there are dozens of so-called "species" with only minor differences. They are continually being revised in their taxonomic status.

Ceratarges is a genus of spiny trilobites. The geologic age of this genus is early to middle Devonian. Its eyes (shown here in brown color) are on long stalks. [Note: well-preserved specimens of this trilobite cost from 600 to 900+ dollars from online fossil dealers]. The sketch of the species shown here, which is based on a figure in Fenton and Fenton,1989, depicts a 4-cm long specimen from Germany. This species is similar to species of this genus found in Morocco. The reason for the many spines is not known, but the spines most likely provided protection from large-sized Devonian predatory fishes (arthrodire placoderms). I shall soon post a blog about these fish, so  "stay-tuned!"

References Consulted:

Fenton, C.L. and M.A. Fenton. 1989. The fossil book. A record of prehistoric life. Doubleday, New York, 740 pp.

Scotese, C. R. 2021. An atlas of Phanerozoic paleogeographic maps: the seas come in and the seas go out. Annual Review of Earth and Planetary Sciences.

Some useful websites (that have many images of trilobites):

jurassic-dreams.com/products [nice images and good information about Acadoparadoxides]

Trilobites.life/Moroccan-trilobites

Fossilicious.com/trilobites-of-morocco

Fossilera.com/fossils-for-sale/trilobites [many images!]

amnh.org/research/paleontology/collections/fossil-invertebrae-collection/trilobite

  this site illustrates Devonian trilobites of the United States (genera in alphabetized order)

 

PUFFERFISH: FAMILY TETRAODONTIDAE

There are about 120 species (some very colorful) of this fish (also known as puffers, blowfish, balloonfish, fugu, swellfish, and globefish) that can inflate up many times its normal size in order not to swallowed whole by a predator. Puffer fish fill their elastic stomachs repeatedly with huge amounts of water, until they enlarge their body size several times their normal size (which can be as much as up to 3 times). They can exhale this water rapidly, if necessary. Pufferfish have no scales; instead, they have spines. Some pufferfish have long spines to also help ward off predators. Thus these pufferfish look like porcupines.

inches wide; from Mexico? Image courtesy of L.T. Groves, Collections Manager of Malacology, Natural History Museum of Los Angeles County, California.

Pufferfish are generally believed to the second-most poisonous vertebrate, after the golden poison frog. The poison of pufferfish is tetrodotoxin, a powerful neurotoxin. There is enough poison in a single pufferfish to kill 30 adult humans, and there is no antidote! Death can occur within three minutes. Interestingly, sharks are immune to pufferfish poison.

Puffer fish is prepared and served as a very expensive delicacy in the Far East. But, if this fish is improperly prepared for human consumption it can cause death (within 24 hours) because nearly all puffer fish species are highly poisonous. In Japan, a special “Chef’s License” is needed to prepare this delicacy, called “fugu.” These chefs know which parts, and how much of them, are safe to eat (Wikipedia).

Pufferfish live in warm waters and are found throughout the tropical (including coral reefs) to subtropical marine waters of the world. A few, however, can live in brackish or even fresh water. The smallest pufferfish are about 8 cm long, and the largest individuals are up to 1 m long. Pufferfish are known for building intricate circular nests, up to 2 m in diameter, in sand.

Some people keep pufferfish as pets. If other fish are in the same aquarium, they have to be alert and quick swimmers to avoid being eaten by the pufferfish, which can have enormous appetites (they especially like to also eat earthworms fed to them).

These fish are named for their four large teeth: two chisel-like teeth in the top of the mouth and two fused into a flattened, broad plate. These teeth are used just like beaks for crushing their natural prey: crustaceans and mollusks. Eating even the shelly parts of their prey keep the puffer fish teeth sharp. Puffer fish have a geologic range from the Eocene to modern day.

Tetraodon lineatus Linnaeus, 1758. From Wikipedia. This species is named for its four teeth (two large chisel-like teeth on upper jaw and two very wide flat teeth on the lower jaw. This can be an aggressive and intolerant fish that should be avoided because its teeth are sharp and its jaws are strong. The teeth grow each day and need to be worn down. This sketch is “based” on an image in Wikipedia.

References Consulted:

keywestaquarium.com

Wikipedia.org

Note: If you a fan of television’s “Homer Simpson” show, you might want to watch--on YouTube for free, Simpson’s Season 2, Episode 11, entitled “One Fish, Two Fish, Blowfish, Blue Fish,” where he eats a whole, a poisonous fugu fish and is told he has less than 24 hours to live. He decides to see what happens, but then he is arrested for drunk driving, etc.  

SOME FOSSILS OF THE PETRIFIED FOREST, NORTHERN ARIZONA

The Petrified Forest is in Petrified Forest National Park, which east of Holbrook, northern Arizona. The exposures of rock strata in this park are part of the Chinle Formation, which based on fossils, are of Late Triassic age (225 to 220 m.y.a.). [As suggested by one of my former students, Matt Ventimeglia, who recently visited the park and sent me many of the images shown below, perhaps the “Petrified Forest“ could also be referred to as “Triassic Park.”] Some of the fossils, which are on view at the museum at the northern part of the park, are shown below. These fossils include petrified logs, ferns, cycads, ginkgoes, phytosaurs, large amphibians, small pterosaurs, and early dinosaurs.

The Petrified Forest (shown by the red dot) was located 4 degrees north of the equator (shown by the green line) during the Late Triassic (218 million years ago), when \ the Pangaea Supercontinent existed. Even since that time, the area of the forest has been slowly creeping northward and westward, via continental drift, which was the result of plate tectonics.

The Tepees in the north-central part of the park are exposures of the Blue Mesa Member of the Chinle Formation. The colorful bands of mudstone and sandstone were deposited during the Late Triassic, when the area was part of an extensive tropical floodplain. Image courtesy of Matt Ventimeglia--2023.

Three images showing petrified tree trunks and associated fragments of petrified wood. The first two images were taken by the author, about 20 years ago. The third image is courtesy of Matt Ventimeglia. Most of the “long” trees are Araucarioxylon arizonicum.

Two images showing sliced sections of petrified “wood” that were slowly “petrified”/”agatized” (i.e., replaced) by underground solutions containing colorful silica material.

Phytosaur skull (image courtesy of Matt Ventimeglia—2023).

Placerias hesternuscopy (image courtesy of Matt Ventimegila—2023).

Rauisuchid (left) and aetosaur (right) with a small pterosaur on its back (near the far wall).

The following information is copied from signage at the museum: “Rauiscdhids (raw-ih-SOO-kids) ranked as the top terrestrial predators of the Late Triassic, thanks to huge skulls armored with powerful biting jaws and 3 inch (7.6 cm) long serrated teeth. Some rauisuchids grew up to 20 feet (6 m) in length. Pauisuchids provide an excellent example of convergent evolution. Though their body plans were similar to meat-eating dinosaurs, like Tyrannnosaurus and Allosarus, who lived later during the Jurassic and Cretaeous, rauiscuhids are more closely related to crocodiles than to dinosaurs.”

The following information is copied from signage at the museum: “Aeteosaurs (AY-e-to-SAWRS) were 3-18 feet (1.-6 m) long, omnivorous reptiles with broad, flat bodies protected by plate-like osteoderms. Some species had large spikes on their sides or back that were possibly used for defense and species recognition. Aetosaurs had sturdy limbs and small skulls with a pointy snout used to root in the soil for plants, roots, and invertebrates. Desmatochus is the largest known aetosaur, reaching lengths of 18 feet (6 m). Although the first fossils of this species were found in Texas, it is relatively common” at the Petrified Forest in Arizona.

Closeup of a duck-size pterosaur (a model) mentioned in regard to the previous image (i.e., the specimen is displayed on the back of the aetoeosaur).

I could not find any information pertaining to the scientific name of this small pterosaur. This is most likely because the specimen/model is based on only  a lower jaw bone (with teeth intact), and not enough of the specimen is present for a positive identification as to genus. Nevertheless, it is the only pterosaur remains found in the Petrified Forest fauna. For your information, the largest pterosaur of all time lived near the end of the Cretaceous Period and was as tall as the modern-day African giraffe.

If you are ever in the neighborhood of the Petrified Forest, do yourself a favor and allow time (one day) to visit this very interesting place.

 

VERY RARE ARTICULATED CHITON FOSSILS

Chitons (also called amphineurans or polyplacophorans) are mollusks that belong to class Polyplacophora. The geologic range of this class is from the Cambrian Period to modern day.

Chitons are sluggish crawlers on the sea bottom and live mostly on hard substrates in very nearshore environments. Chitons can, however, also live on sunken wood or on hard substrates in deep-water (bathyal) offshore environments, where cold seeps have formed rocky edifices. Fossils of chitons specimens are usually uncommon to rare and almost always consist of disarticulated valves (i.e., broken apart).

The chiton shell consists of eight dorsally located, aragonite plates (valves) that overlap posteriorly. The anteriormost valve (head plate) has indentations on its front edge. The valves are surrounded by a band of tough, organic material (girdle) that is formed by the mantle as a soft part and is quite flexible. In a few chitons, the dorsal shell may be concealed entirely by organic material. The underside of a chiton is mostly a broad flat muscular foot. If disturbed, the chiton can roll up like a "pill bug," bending at each joint between the dorsal plates.

Sketches of the dorsal, ventral, and side views showing the morphology of a chiton (shell and soft parts).

Unless burial is quick, preservation of fully intact (i.e., with articulated valves all present) chiton shells in the sedimentary/fossil record is extremely rare. To date, there have been only six reports in the published literature of articulated fossil chitons. Squires and Goedert (1995) reported on one of the two oldest known of these occurrences, namely, in late middle Eocene to early late Oligocene cold-seep limestones, Olympic Peninsula, Washington. They identified the chitons to be the extant species Leptochiton alveolus (Lovén, 1846), which is one of two known, modern-day cosmopolitan species of chiton. This species is present in the Pacific, Atlantic, Indian oceans, and in the Mediterranean Sea. Its favored habitat is in bathyal to abyssal depths (see Squires and Goedert, 1995, p. 51).

Three views (dorsal, ventral, and side) of a modern-day chiton shell (without its encircling girdle) with its valves glued-back together. The “head” area is at the top of the first two images and to the right in the third image.

Leptochiton alveolus (Lovén, 1846) from the upper part of the Lincoln Creek Formation, early late Oligocene age, Washington; specimen is 1.6 cm length. Image is from Squires and Goedert (1995, fig. 3). This remarkably rare specimen was found by Jim Goedert. 

Leptochiton alveolus (Lovén, 1846 ), modern day, Peru; specimen is 2.2 cm length. Image is from Squires and Goedert (1995, fig. 6). 

The only other presently known Eocene occurrence of an articulated chiton (Leptochiton sp.) was reported by Cabrera and Olivero (2011) from Anarctica.  

References Cited:

Cabrera, M.I.L and E.B. Olivero 2011. An Eocene articulated Polyplacophora (Mollusca) from the La Meseta Formation, Antartica and the stratigraphy of the fossil-bearing strata. Journal of Paleontology 85(5):970–976.

Squires, R.L. and J.L. Goedert. 1995. An extant species of Leptochiton (Mollusca: Polypolacophora) in Eocene and Oligocene cold-seep limestones, Olympic Peninsula, Washington. The Veliger 38(1):47–53. Pdf is available for free via Biodiversity Heritage Library (www.biodiversitylibrary.org). 

LARGEST POISONOUS SNAKE FANGS EVER

Snakes evolved probably from burrowing lizards during Cretaceous time. The first poisonous snakes are believed to have first appeared during Miocene time. 

The extant Gaboon viper snake (also called the Gaboon adder snake), whose scientific name is Bitis gabonica, is VERY poisonous (its dried venom has a strength of 200 to 1000 mg [note: it only takes 14 mg of venom is enough to kill a human (Wikipedia), and these snake bites are definitely known to have killed humans]. Its venom contains neurotoxin and hemotoxin) (Animal Diversity Web). This snake has the highest venom yield of any animal (Wikipedia). Also, their venom glands are enormous, thus they inject large amounts of venom; in addition, this snake does not release after it bites (Wikipedia). This snake strikes at a speed of 175 to 200 miles per hour). It lives in tropical rainforests, as well as in savannas, of sub-Saharan central Africa. Its geographic distribution is widespread (Animal Diversity Web). 

Gaboon viper (my sketch is based on, and modified from, an image on Animal Diversity Web.org).

This snake can be up 6 feet, 9 inches long and weight up to 45 pounds (typically less than or equal to 25 pounds). They are the heaviest snakes known, relative to their somewhat short and stout bodies. Their head is large and triangular, with a pair of “horns” between the raised nostrils. Their fangs are up to 2.3 inches long, thus they have the world’s longest fangs for any snake, hence their fangs can go very deep into the body of their prey. They are nocturnal ambush predators, but compared to many other vipers, the Gaboon viper is a sluggish animal. Their complexly colored skin, which can be highly variable in its color, provides excellent camouflage. They are most active around sunset and lie perfectly still, blending in extremely well with leaf litter on the forest floor.

References Consulted: Both are very informative.

Animal Diversity Web. Bitis gabonica Gaboon Viper. University of Michigan, Museum of Zoology.

en.Wikipedia.org

THE IRON SNAIL

This gastropod, whose scientific name is Chrysomallon squamiferum Chen et al., 2015 [the genus name means "golden hair," for the pyrite coating often found on the shell; the species name means “scale-bearing.”] This snail is unique as it is the only known extant animal that incorporates iron sulfide into its shell and into its sclerites (= small to microscopic-sized hard-body parts). It was discovered in April, 2001 in the Indian Ocean, where it lives in the deep-sea hydrothermal-vent areas. 

Ocean-floor map of a portion of the Indian Ocean showing the approximate locations of the three sites (yellow dots) where C. squamiferum has been found (to date). Note: These locations all occur on oceanic ridges, mainly at or near the “Rodriques Triple Junction”-ridge complex, east of Madagascar. The map is a portion of a “National Geographic Society map” (1967).

This deep-sea hydrothermal-vent gastropod lives at depths between 2,415 to 2,460 m [7,923 to 7,923 ft.). It lives adjacent to both acids and reducing-vent fluids on the walls of “black smoker” chimneys, or directly on diffuse sites where fluids are flowing out. There is high concentration of hydrogen-sulfide gas and low concentration of oxygen. The temperature of the waters/fluids is between 2 and 10° C. The substrate rock is troctolite and mid-oceanic basalt.

This gastropod is an obligate symbiotroph that obtains all of its nutrition from the chemoautotrophy of its endosymbiotic bacteria. It is not a filter feeder. Its radula (in the mouth area) is small. It is likely that this gastropod has a planktonic dispersal stage, which is in accordance with its scattered locations (see Map above).

Oblique side view of an actual shell of C. squamiferum and a small piece of pyrite that was once attached to the gastropod animal but fell off later. Aperture of shell is 28 mm wide. This shell was retrieved from a depth of 2,440 m, at the base of a black smoker in the Kairei Vent Field, at the Rodriques Triple Junction, west of Madagasgar, in the Indian Ocean. Image courtesy of L.T. Groves, Collection Manager, Natural History Museum of Los Angeles County, California. 

                               A

                               B

Two views (sketches by the author) of C. squamiferum (A) oblique top view of shell and animal. (B) Apertural view of an empty shell. This snail is up to 45.5 mm in maximum shell dimension. Its coiled shell consists of three whorls; its spire is compressed; and its long aperture has an elliptical shape.

The shell of this gastropod has three layers: outer layer of iron sulfides, middle organic layer = periostracum, and innermost layer aragonite [= calcium carbonate]. The sides of its foot are armored (hence the common name “scaly foot,”) with hundreds of iron-mineral sclerites composed of the minerals: pyrite (iron sulfide) and greigite (an iron sulfate). This latter biomineral is only known to occur in this gastropod. Chrysomallon squamiferum also has an operculum (a “trap door” than closes off the opening of the shell), but it becomes less functional as the animal gets bigger.

Associated fauna found with this gastropod includes sea anemones, bivalve mussels (e.g., Bathymodiolus), several other gastropods [e.g., Lepetodrillus and Pseudorirmula) and slit limpets], annelids, crustaceans, echinoderm holothurians, and fish.

To date, Chrysomallon does not have a fossil record although fossil-hydrothermal vents (at ridges and next to subduction zones) are well documented in the literature.

Classification

Phylum Mollusca

Class Gastropoda

Order Neomphalida

Family Peltospiridae

Genus Chrysomallon Chen, Linse, Copley, and Rogers, 2015

Species Chrysomallon squamiferum Chen et al., 2015

 

Reference Cited:

Chong, C. K. Linse, J.T. Copley, and A.D. Rogers. 2015. The “scaly-foot gastropod”: a new genus of hydrothermal vent-endemic gastropod (Neomphalina: Peltospiridae) from the Indian Ocean. Journal of Molluscan Studies 81:322–334. (pdf is free and readily accessible).