ENTELODON: SO-CALLED “KILLER PIGS”

Entelodon [the name means “complete teeth”) were large pig-like mammals that lived in forests of the northern continents, especially Europe. They are classified as entelodontids. They were not true pigs, and the moniker “killer pigs” is very misleading. Molecular studies indicate that Entelodon was more closely related to hippos and cetaceans (whales) than to pigs or peccaries.

Entelodon sp. (length 2 m), from the Oligocene of Europe. 

      Classification (from Wikipedia, 2024):

Kingdom Animalia

Phylum Chordata

Class Mammalia

Order Artiodactyla (= even-toed ungulates)

Suborder Suina

Family Entelodontidae

Genus Entelodon

Entelodon teeth are similar to pigs [i.e., dentition formula 3.1.4.3/3.1.4.3] --- namely, each row has three pairs of robust incisors, a pair of large canines, four pairs of premolars, and three pairs of simple flat molars. For an explanation of mammal dentition, see one of my earlier posts that discusses this subject matter. Entelodon incisors were commonly stout and blunt and their canines robust, suggesting that Entelodon was an omnivore and especially good at browsing (for nuts and fruit, branches, and carrion?). Its adult teeth were especially good for crushing and grinding. 

This genus ranged from the late Eocene to early Miocene (38 to 19 million years ago) and lived in Europe, Asia, and North America. They were most common during the Oligocene, especially in Europe. They were never abundant in North America although they survived there until the early Miocene. 

Entelodon resembled a large wild boar. Entelodon’s length was about two meters. Most individuals were no taller (at the shoulder) than about 6 feet. They were strong shouldered and had a bison-like spinal hump and a heavy head. They also had a huge head, and their cheekbones developed huge flanges that projected downwards and outwards. Also, the underside of their lower jaw had one or two pairs of knob-like tubercles that were variable in size from individual to individual.

[Note: The largest known entelodonid [genus Daeodon] lived in North America. It was up to 1650 pounds in size and reached almost 7 feet tall at the shoulder].

Entelodon could have run well but probably not at high speeds nor for too long. 

REFERENCES CONSULTED

Savage, R.J.G. and M.R. Long, 1986. Mammal evolution (an illustrated guide). British   Museum (Natural History), 259 pp.

Wikipedia. 2024. 

OSTRICHES

They are the largest flightless birds living on Earth today. They can be up to 9 feet tall and weight up to 300 pounds. They have the fastest land speed of any bird. They can run steadily up to 34 mph, and can run up to 43 mph, for short durations. They have also the largest eyes of any land vertebrate. They have claws at the end of their wings. For a comparsion of the size of the ostrich egg to that of a modern chicken, see my June 11, 2022 blog. 

Their earliest relatives (referred to as “paleotididae struthioniformes”) were widely distributed, as early as the late Eocene in Asia, Europe, and, to a lesser degree, in North America. The first true ostriches first appeared in Africa during the early Miocene, and, today, wild ostriches are confined to Africa (Mayr et al. 2021). Some escaped ostriches in Australia represent feral populations.

CLASSIFICATION (see Wikipedia, 2024)

Class Aves [=birds)

Order Struthioniformes [=ratites]

Family Struthionidae

Genus Struthio Linneaus, 1758, type species S. camelus Linneaus, 1758

       

Species:

S. camelus camelus = “red-necked,” North African ostrich they  are the most wide ranging ostrich but do not live in the Sahara Desert region).

S. c. australis = “black-necked,” South African ostrich

S. c. massaicus = “pink-necked,” Masai ostrich (central eastern Africa)

S. molybdophanes = “bluish-necked,” southern Ethiopia, NE Kenya, and Somalia

Two individuals of Strutio molybdonphanes (showing color variation) living at the Living Desert Zoo and Gardens in Palm Desert, Riverside County, southern California.

References Cited

Mayr, G. and N. Zelenkov. 2021. Exintct crane-like birds (Eogruidae and Ergilornithi) from the Cenozoic of central Asia are indeed ostrich precursors. Orthnithology 138(4):1-15. Pdf is free.

Wikipedia. 2024. Ostriches. 

GIRAFFES

They are the tallest mammals today, have an even number of toes, and are geographically limited today to central Africa. Why giraffes have such long necks is still resolved; for example, do the long necks help obtain food more easily, and/or did their long necks evolved to be used for battle against other giraffes? Perhaps, it is for both reasons.

Figure 1: A juvenile giraffe living at the Los Angeles County Zoo. The author took this picture about 30 years ago.

Figure 2: A typical giraffe skull. The dental formula is 0/3, 0/1, 3/3, 3/3 = 32 teeth(see one of my earlier posts that discusses the details of how to determine dental formulae of vertebrates. Note that the upper canine teeth are absent. Also, this skull shows the  three unbranched “horns” typically present in both sexes. As shown here, the unique third bone is often found (especially in males) is in front and between the other two horns (Lawlor, 1979). 

Determining how many living species there are of giraffes has historically not been an easy task. There has been little or no agreement about this matter, which has been going on over many years now.   

Back in the early 1900’s, workers claimed that there is only a single species and nine subspecies. Woolston (2016) did a detailed study of 97% of giraffe’s DNA and determined that there are four species. Subsequent DNA studies by Fennessy et al. (2017) and Coimbra et al (2021) corroborated this number. Nevertheless, in 2023, the number of any possible subspecies ranges continues to be reported by various workers, as from two to four (usually four).

For those who are interested, Pheasant (year not given) has a blog post that agrees that there are four giraffe species. He also included a useful distribution map, showing that most of them live today only in the southern half of Africa [none live in the Sahara region]. They evolved and separated and have not crossbred, thereby there has not been any exchange of genetic material for millions of years. Only about 100,000 giraffes are estimated to be living “in the wild,” and as in the case of other large land mammals, their numbers are dwindling.

Giraffes range in geologic time back as far as about 20 million years ago (i.e., early Miocene). Their long necks first appeared even as early as the Miocene. Even then, they lived in forests. About 8 million years ago, when climate changes caused their eating habits to changes, they started adapting to living in more-open areas.They are most closely related to pronghorns, deer, antelopes, buffalo, goats sheep, and cattle (Wikipedia, 2024).

Classification:

ORDER Artiodactyla

FAMILY Giraffidae

Genus Giraffa

4 Species 

  giraffa---------------southern giraffe, mainly So. Africa, Namibia, & Botswana

  tippelskirchi--------Masai giraffe, in Tanzania, Kenya, and Zambia

  reticulata-----------G. cameloparadis, scattered groups in central and eastern Africa 

 cameloparadalis---G. camelopardalis, in Ethiopa and South Sudan

note: some authors, but not all, recognize “subspecies” 

Genus Okapia (has zebra-like stripes on its posterior and legs)

1 Species

  johnstoni---limited geographically to central-African rain forests

Figure 3. Okapia johnstoni. This relative of giraffes is about 5 feet tall (at the shoulder) and weights about 440 to 770 pounds. It is mainly active during the day and lives a solitary life in dense forests in the Congo region of central Africa, at 1600 to 4,900 feet in elevation. It eats leaves, fruit, and fungi. The Okapia has an extremely long tongue that can clean its eyes and ears. 

Other Comments:

Although nearly all giraffes are reticulated (consisting of connected “spots”), some genetic mutants have a solid brown color (Maron, 2024). Examples like the latter show that relying on color patterns for identifying a species is not always reliable, yet the very similar geometric and color patterns of giraffes are given heavy emphasis for identification as to species.

I have attempted to decipher, via illustrations in the literature, how the so-called different species of giraffes are differentiated by the shapes and sizes of their spots/reticulations. My attempts were frustratingly inconclusive.

REFERENCES CITED

Coimbra, R.T. F. and others. 2021. Whole-genome analysis of giraffe supports four  distinct species. Current Biology 31:2929-2938.

Lawlor, T. E. 1979. Handbook to the orders and families of living mammals. Second edition. Mad River Press, Eureka, California, 327 pp. 

Pheasant, T. year unknown. The four giraffe species explained. Bonamy (an online blog)

Maron, D.F. 2024. On the coat tales. National Geographic. January, 2024, p. 25.

Wikipedia. 2024

 

Woolston, C. 1026. DNA reveals that giraffes are four species, not one. Nature 537:290-291.

 "SHOVEL TUSKERS": EARLY ELEPHANT-LIKE ANIMALS 

The "shovel tuskers," or ambelodontids are an extinct family of proboscideans. Early workers classified them as gomphopheres (see one of my previous posts) because they look similar in body shape and size and have tusks. The lower tusks of ambelodontids however are strikingly different as they are flattened and closely spaced (nearly fused in some species), thereby forming an effective spatulate “shovel” for putting vegetation in their mouths.

About eight genera of ambelodontids are known. Most are only Miocene in age. At least four are endemic to North America (e.g., Ambelodon, Eurybelodon, Konobelodon, and Serbelodon). The latter genus is of Miocene age and is known from the Miocene Dove Spring Formation in Southern California, as well as from Pliocene rocks in Nebraska. 

Two other genera, Archaeobelodon and Platybelodon are found in North Africa and Europe, and Aphanobelodon is found in China. 

Head view of Platybelodon.

Reference

    Osborn, H. F. 1933. Serbelodon burnhami, a new shovel tusker from California. American Museum of Novitates no. 639.

William More Gabb: California’s First State Paleontologist

Although he lived only 39 years (1839–1878), he was a very productive researcher/scholar. Gabb introduced 1163 fossil taxa and authored 40 papers. For an annotated catalog of all of the fossil invertebrates described by, and named for Gabb, as well as a complete list of his publications, see Groves and Squires (2018).

Gabb was born in Philadelphia, and he received his education there, where he was influenced by Timothy Conrad, the curator of the Museum of Academy of the Natural Sciences in Philadelphia. In 1862, two years after the Geological Survey of California was formed, Gabb was hired to survey California’s geology. On his first assignment, he and his colleagues traveled via horseback, from San Francisco southward to northern Los Angeles County, in order to study the details of the paleontology of this region. Gabb’s (1864a, 1864b) reports were first papers on the Paleontology of California fossils. 

In 1869, Gabb left the Geological Survey of California, and for the next few years visited and did paleontologic work on Tertiary molluscan fossils, as well as natural history work on animals he found in the jungles, in the Amazon region of Peru and in Central America.  Savage (1970) wrote an interesting account of his work in Costa Rica. While in Costa Rica, he contracted a deadly form of malaria. For the next five years, his health deteriorated, and in May 1878, his short but scholarly career ended, when he died in Philadelphia. 

References Cited:

Gabb, W.M. 1864a. Description of the Triassic fossils of California and their adjacent territories. In Palaeontology of California. Geological Survey of California, v. 1, section 1, pp. 19–35, pls. 3-6.

Gabb, W.M. 1864a. Description of the Tertiary invertebrate fossils and synopsis of the Tertiary fossils of California. In Palaeontology of Califoria, Geological Survey of California, v. 2, section. 1, pp. 1-124, plates 1-18.

Groves, L.T. and R.L. Squires. 2018. Annotated catalog of the fossil invertebrates described by, and named for, William More Gabb (1839–1878). Zootaxa 4534 (1):1–150.  <http.www.mapress.com/j/zt/>

Savage, J.M. 1970. On the trail of the golden frog: with Warszewicz and Gabb in Central America. Proceedings of the California Academy of Sciences, Fourth Series, 38:273–280.

 Squires, R.L. 1999. William More Gabb First Paleontologist of the Geological Survey of California. California Geology, July/August 1999:11–14.

 

PUFFINS: Not Just Arctic Birds

Puffins are small-sized pelagic seabirds (also called auklets) that feed by diving into the ocean, where they feed on zooplankton, small fish [such as herring], and small squids. These birds are perfectly adapted to life at sea. They can even drink seawater, and they are exceptional swimmers. They are fast flyers (up to 55 miles/hour, and they usually fly only a few feet above the water line.

Classification:

Class Aves

Order Charadriiformes

Family Alcidae

Genus Fratercula (type species: Alca arcica Linnaeus, 1758)

Fratercula is Latin for “little brother of the north.” They probably received their scientific name because of their black-and-white plumage, which resembles a friar’s robe.

A group of puffins is called by various names: a colony, a circus, a puffinry, a gathering, a burrow (because some species rest in burrows, up to 3 feet deep—other species, however, nest on cliffs. Chicks are called a puffling. Puffins mate for life and return to the same burrow, year after year. They are very social birds.

Today, there are three recognized species of puffins:

Fratercula arctica (also called the “North Atlantic puffin” (this is the smallest in size of the puffins today); it lives in northern Europe, Faroe Islands, Iceland, Greenland, Norway, Atlantic Canada and south to Maine, New York, and even Morocco.  

Fratercula corniculata (also called the “North Pacific puffin” or the “Horned puffin”); it lives in the north Pacific coasts of Siberia, Alaska, and British Columbia; it winters south to California and Baja California, Mexico.

Fratercula corniculata (13 to 15 inches long and 13 ounces to 1.7 pounds weight).

Fratercula cirrrhata (also called the “tufted puffin” or the “crested puffin”) (this is the largest in size of the puffins today—reaching 15 inches long and weighing up to 1.7 pounds); it lives in the North Pacific, British Columbia, southeast Alaska, Aleutian Islands, Kamchatka, Kuril Islands, Sea of Okhotsk; it winters south to Honshu, Japan and to California.

Two views of an adult Fratercula corniculata. Photos taken at the Monterey Bay Aquarium, Monterey California, where they have a rocky shoreline “live” exhibit of puffins. Images courtesy of a member of my family (Summer, 2023).

Puffins originated in the Pacific area and later migrated to the Arctic area, undoubtedly when the climate changed, starting during Pliocene time.

The geologic range of puffins is middle Miocene to recent. Late Pleistocene fossils of the extinct puffin, Fratercula dowi, have been found on San Miguel and San Nicolas islands in the Channel Islands of southern California (Guthrie et al. 2002).

References Used:

Guthrie, D.A., et al. 2002. A new species of extinct Late Pleistocene puffin (Aves, Alcidae) from the southern California Channel Islands. Proceedings of the Fifth California Islands Symposium, U.S. Department of Interior, Pp. 525–530.

en.Wikipedia.org 

SOME TWISTED SNAIL SHELLS

This post concerns some marine gastropod (snail) shells that are irregularly coiled (twisted). In the 1950’s to 1960’s, workers assigned all irregularly coiled marine gastropods to family Vermetidae. Now, however, such snails are assigned to family Turritellidae, subfamily Vermiculariinae. These changes are examples showing that, these days, seashell classifications are “fluid” concepts and always subject to being revised.

Family Turritellidae, subfamily Vermiculariinae, Vermicularia knorri (Deshayes, 1843), 1.5 cm “width” of shell (from left to right of its mid-section, as viewed here). This species is common in the Gulf of 

Mexico (e.g., Florida, Cuba, Jamaica, and Puerto Rico). 

Family Turritellidae, subfamily Vermiculariinae, Vermicularia knorri (Deshayes, 1843), 2 cm “width” of shell (from left to right of its mid-section, as viewed here). The color of the shell of this species is variable. This species is common in the Gulf of Mexico (e.g., Florida, Cuba, Jamaica, and Puerto Rico). 

This gastropod shell (length 8 cm) is Tenagodus ponderosus (Mörch, 1861), an uncommon species that lives in shallow-marine depths in the waters off Queensland, Australia southwest Pacific. It is a prime example of twisted shells with a slit in their shells: thus belonging to family Siliquaridae. 

For those that are interested, I wrote a paper (Squires, 1990) about my recognition of a new Paleocene species of genus Tenagodus based on my field work in southern California. 

                                        AN "END" NOTE

While examining my small collection of modern-day, irregularly coiled gastropod shells, I came across an unusual vermetid that I found many years ago as float on the beach at Coal Oil Point, Goleta,, Ventura County, southern California (illustrated below). It is noticeably different from other southern California vermetids by having a shell  much larger in diameter and also much much darker in color.

Two views (side and top) of an unusual vermetid (9.5 cm length, 4.7 cm wide at its base, 2.2 cm diameter at its top) from Coal Oil Point, Goleta,Ventura County,  southern California.

Identification of this unusual twisted gastropod proved to be problematic. Via the internet (Wikipedia and Invert-E-Base), I detected images of Thylacodes colubrinus, formerly known as Serpulorbis colubrinus. Thylacodes now belongs to family Vermetidae. Thylacodes colubrinus is known from China and the Philippines. Although somewhat blacker than the Goleta specimen, T. colubrinus is closer in morphology to it than any other vermetid I know about.

I contacted Lindsey Groves, Malacology Collection Manager at the Natural History Museum of Los Angeles County. He kindly provided me with photos (two included below) of the T. colubrinus from the Philippine Islands.

Thylacodes colubrinus from the Cebu Province, Philippine Island. Images of two specimens from the same cluster, courtesy of L. T. Groves. The straight-tube specimen is 2 cm long, and the other specimen is 3.5 cm long.

It is mystery how a vermetid that strongly resembles a species from the Philippines might occur in southern California. Its occurrence at Goleta is probably either accidental or on purpose. In situ collecting will be required to resolve whether or not this species positively occurs in California.

REFERENCES USED or CITED:

Invert-E-Base [via the WoRMS website]. 2024.

Squires, R.L. 1990. New Paleogene siliquariid and vermetid gastropods from the Pacific coast of southwestern North America. The Veliger 33(2):286–292, figs. 1-10. (pdf is free, via the website biodiversity library.

Wikipedia. 2024.

WoRMS, 2023: marinespecies.org