William Hay Caldwell

Last updated • 1 min readFrom Wikipedia, The Free Encyclopedia

William Hay Caldwell (1859 – 28 August 1941) was a Scottish zoologist. [1] Attending Cambridge University, he was the first recipient of a studentship founded in honour of his supervisor Francis Maitland Balfour, who died in a climbing accident in 1882. [2] Two years after graduating from Cambridge in 1880, Caldwell was appointed Demonstrator in Comparative Anatomy, working for Professor Alfred Newton. In 1884, Caldwell used his studentship, which consisted of "£200 studentship, a £500 grant, the prestige and backing of the Royal Society, and letters of introduction from Newton to travel to Australia" to investigate whether the platypus laid eggs. With the assistance of the local Aboriginals, Caldwell set up camp on the banks of the Burnett River in northern Queensland, hunting for lungfish, echidna, and platypus eggs. [3] After extensive searching assisted by a team of 150 Aboriginals, he discovered a few eggs. Mindful of the high cost per word, Caldwell famously but tersely wired London, "Monotremes oviparous, ovum meroblastic". That is, monotremes lay eggs, and the eggs are similar to those of reptiles in that only part of the egg divides as it develops. [4] Caldwell stayed away from the beginning stages of Darwinism and wanted to study evolutionary patterns himself. He believed that patterns of individual development could assist in developing and understanding the process of evolution. [5] Platypus and echidna specimens collected by him and stored, but not catalogued, in the Cambridge University Museum of Zoology were rediscovered in 2022. [6]

Related Research Articles

Platypus Species of mammal

The platypus, sometimes referred to as the duck-billed platypus, is a semiaquatic, egg-laying mammal endemic to eastern Australia, including Tasmania. The platypus is the sole living representative or monotypic taxon of its family (Ornithorhynchidae) and genus (Ornithorhynchus), though a number of related species appear in the fossil record.

Echidna Family of mammals

Echidnas, sometimes known as spiny anteaters, are quill-covered monotremes belonging to the family Tachyglossidae. The four extant species of echidnas and the platypus are the only living mammals that lay eggs and the only surviving members of the order Monotremata. The diet of some species consists of ants and termites, but they are not closely related to the true anteaters of the Americas, which are xenarthrans. Echidnas live in Australia and New Guinea.

<i>Obdurodon</i> Extinct genus of monotremes

Obdurodon is a genus of extinct platypus-like Australian monotreme which lived from the Late Oligocene to the Late Miocene. Three species have been described in the genus, the type species Obdurodon insignis, plus Obdurodon dicksoni and Obdurodon tharalkooschild. The species appeared much like their modern day relative the platypus, except adults retained their molar teeth, and Unlike the platypus which forages on the lakebed, they may have foraged in the water column or surface.

Prototheria Subclass of mammalia

Prototheria is a subclass to which the orders Monotremata, Morganucodonta, Docodonta, Triconodonta and Multituberculata have been assigned, although the validity of the subclass has been questioned.

<i>Steropodon</i> Extinct genus of monotremes

Steropodon galmani is a prehistoric species of monotreme, or egg-laying mammal, that lived about 105 to 93.3 million years ago (mya) in the Early to Late Cretaceous period. It is one of the oldest monotremes discovered, and is one of the oldest Australian mammal discoveries.

Teinolophos is a prehistoric species of monotreme, or egg-laying mammal. It is known from four specimens, each consisting of a partial lower jawbone collected from the Wonthaggi Formation at Flat Rocks, Victoria, Australia. It lived during the late Barremian age of the Lower Cretaceous.

Long-beaked echidna Genus of monotremes

The long-beaked echidnas make up one of the two extant genera of echidnas, spiny monotremes that live in New Guinea; the other being the short-beaked echidna. There are three living species and one extinct species in this genus. The extinct species were present in Australia. Echidnas are one of the two types of mammals that lay eggs, the other being the platypus. The echidnas retain reptilian features such as egg-laying but display mammalian features such as fur and lactation.

Electroreception and electrogenesis Detection of weak electric fields, via specialized sense organs and brain structures

Electroreception and electrogenesis are the closely-related biological abilities to perceive electrical stimuli and to generate electric fields. Both are used to locate prey; stronger electric discharges are used in a few groups of fishes to stun prey. The capabilities are found almost exclusively in aquatic or amphibious animals, since water is a much better conductor of electricity than air. In passive electrolocation, objects such as prey are detected by sensing the electric fields they create. In active electrolocation, fish generate a weak electric field and sense the different distortions of that field created by objects that conduct or resist electricity. Active electrolocation is practised by two groups of weakly electric fish, the Gymnotiformes (knifefishes) and the Mormyridae (elephantfishes), and by Gymnarchus niloticus, the African knifefish. An electric fish generates an electric field using an electric organ, modified from muscles in its tail. The field is called weak if it is only enough to detect prey, and strong if it is powerful enough to stun or kill. The field may be in brief pulses, as in the elephantfishes, or a continuous wave, as in the knifefishes. Some strongly electric fish, such as the electric eel, locate prey by generating a weak electric field, and then discharge their electric organs strongly to stun the prey; other strongly electric fish such as the electric ray electrolocate passively. The stargazers are unique in being strongly electric but not using electrolocation.

Short-beaked echidna Spiny furred egg-laying mammal from Australia

The short-beaked echidna is one of four living species of echidna and the only member of the genus Tachyglossus. It is covered in fur and spines and has a distinctive snout and a specialized tongue, which it uses to catch its insect prey at a great speed. Like the other extant monotremes, the short-beaked echidna lays eggs; the monotremes are the only living group of mammals to do so.

Western long-beaked echidna Species of monotreme

The western long-beaked echidna is one of the four extant echidnas and one of three species of Zaglossus that occur in New Guinea. Originally described as Tachyglossus bruijnii, this is the type species of Zaglossus.

Eastern long-beaked echidna Species of monotreme

The eastern long-beaked echidna, also known as Barton's long-beaked echidna, is one of three species from the genus Zaglossus to occur in New Guinea. It is found mainly in the eastern half at elevations between 2,000 and 3,000 metres.

James Peter Hill Scottish embryologist

James Peter Hill FRS was a Scottish embryologist.

The mammals of Australia have a rich fossil history, as well as a variety of extant mammalian species, dominated by the marsupials, but also including monotremes and placentals. The marsupials evolved to fill specific ecological niches, and in many cases they are physically similar to the placental mammals in Eurasia and North America that occupy similar niches, a phenomenon known as convergent evolution. For example, the top mammalian predators in Australia, the Tasmanian tiger and the marsupial lion, bore a striking resemblance to large canids such as the gray wolf and large cats respectively; gliding possums and flying squirrels have similar adaptations enabling their arboreal lifestyle; and the numbat and anteaters are both digging insectivores. Most of Australia's mammals are herbivores or omnivores.

Australosphenida Subclass of mammals

The Australosphenida are a clade of mammals, containing monotremes and their extinct relatives. Today, there are only five surviving species of monotreme which live in Australia and New Guinea. Fossils of australosphenidans have been found from the Jurassic of Madagascar and Argentina, as well as the Cretaceous of Australia. The surviving species consist of the platypus and four species of echidna. Contrary to other known crown mammals, they retained postdentary bones as shown by the presence of a postdentary trough. The extant members (monotremes) developed the mammalian middle ear independently.

Henry (Harry) James Burrell OBE was an Australian naturalist who specialised in the study of monotremes. He was the first person to successfully keep the platypus in captivity and was a lifelong collector of specimens and contributor of journal articles on monotremes.

<i>Murrayglossus</i> Extinct species of monotreme

Murrayglossus is a genus in the family Tachyglossidae. It contains a single species, Murrayglossus hacketti, the giant echidna, an extinct species of echidna from Western Australia that is dated to the Pleistocene. It is known only from a few bones. It was about 1 m (3.3 ft) long and probably weighed about 30 kg (66 lb). This makes it the largest monotreme known to have ever lived. Historically treated as a species of long-beaked echidnas, it was separated into its own genus Murrayglossus in 2022. The generic name combines the last name of paleontologist Peter Murray and glossus, the Greek word for "tongue".

Zaglossus robustus is an extinct species of long-beaked echidna known from the middle Miocene of Gulgong, New South Wales, Australia. It may belong in the genus Megalibgwilia. The supposed fossil platypus Ornithorhynchus maximus was based on a humerus of this species.

Johann Wilhelm Haacke was a German zoologist born in Clenze, Lower Saxony, who served as Director of the South Australian Museum in Adelaide from 1882 to 1884.

Monotreme Order of egg-laying mammals

Monotremes are prototherian mammals of the order Monotremata. They are one of the three main groups of living mammals, along with placentals (Eutheria) and marsupials (Metatheria). Monotremes are typified by structural differences in their brains, jaws, digestive tract, reproductive tract, and other body parts compared to the more common mammalian types. In addition, they lay eggs rather than bearing live young, but, like all mammals, the female monotremes nurse their young with milk.

Yinotheria Subclass of mammals

Yinotheria is a proposed basal subclass clade of crown mammals uniting the Shuotheriidae, an extinct group of mammals from the Jurassic of Eurasia, with Australosphenida, a group of mammals known from the Jurassic to present of Gondwana, including living monotremes. Today, there are only five surviving species of monotremes which live in Australia and New Guinea, consisting of the platypus and four species of echidna. Fossils of yinotheres have been found in England, China, Russia, Madagascar and Argentina. Contrary to other known crown mammals, they retained postdentary bones as shown by the presence of a postdentary trough. The extant members (monotremes) developed the mammalian middle ear independently.

References

  1. Bidder, G.P. (1941). "Mr. W. H. Caldwell". Nature. 148: 557–559. Bibcode:1941Natur.148..557B. doi:10.1038/148557a0.
  2. Blackman, Helen (2007). "Lampreys, lungfish and elasmobranchs: Cambridge zoology and the politics of animal selection". The British Journal for the History of Science. 40 (3): 413–437. doi:10.1017/s0007087407009818. JSTOR   4500750.
  3. Hall, B. K. (1999). "The paradoxial platypus". BioScience. 49 (3): 211–218. doi: 10.2307/1313511 .
  4. Grant, J.R. "Fauna of Australia: chapter 16" (PDF). Australian Biological Resources Study (ABRS). Retrieved 26 June 2013.
  5. Rose, Deborah B. "Dislocating the Frontier." Anu.edu.au. N.p., n.d. Web. 16 Sept. 2013
  6. Harris, Rob (13 May 2022). "Lost 150-year-old platypus specimens that stunned the world discovered in UK museum". Sydney Morning Herald. Retrieved 13 May 2022.