Hammerhead sharks aren't the only species with hammer-shaped heads. Check out the rest of the animal kingdom's hammerheads

The hammerhead sharks aren't the only species in the animal kingdom possessing hammer-shaped heads. In the animal kingdom, there are more animals than the hammerhead shark, having heads similar in shape to that of the hammer.

Hammerhead Bat

Male Hammerhead bat by Sarah H. Olsonv via WCS

The hammer-headed bat (Hypsignathus monstrosus), also known as the hammer-headed fruit bat and big-lipped bat, is a megabat found in West and Central Africa. It is the largest bat in continental Africa, with wingspans approaching 1 m (3.3 ft) and males almost twice as heavy as females. Males generally have boxy heads with enormous lips, whereas females have more foxlike faces due to their narrower snouts. 

Hammer-headed bats, along with being Africa's largest bat species, also hold the title of being the most sexually dimorphic bat. 

The bats are frugivorous, consuming various fruits such as figs, bananas, and mangoes,though there have been a few reports of carnivory.

It has been investigated to be a possible reservoir of the Ebola virus, with several testing positive for antibodies against the virus.

Atopodentatus

Atopodentatus by Nick fraser via IVPP 

Atopodentatus (meaning "Strange toothed") is an extinct species of basal sauropterygian known from the early Middle Triassic (Pelsonian substage, Anisian to Ladinian stage) of Luoping County, Yunnan Province, southwestern China. It is believed to have lived between 247 and 240 million years ago, during the Middle Triassic period. 

According to paleontologists, Atopodentatus was 2.75 meters (9.0 ft) long and currently is the earliest known herbivorous marine reptile. Originally, it was thought that the Atopodentatus' upper mandible had small teeth running along the jawline and then up along a vertical split in the middle of the upper jaw. This created the appearance of a "zipper smile of little teeth" on the upper jaw. It was thought that the upper jaw hooked downwards. However, discoveries in 2016 revealed that Atopodentatus had a hammer-shaped head with a bank of chisel-shaped teeth that were useful in rooting the seabed for food.

Stalk-eyed fly

Male hammerhead fly by Kiddopedia via Twitter

The Stalk-eyed flies are insects of the fly family Diopsidae. The family is distinguished from most other flies by most members of the family possessing "eyestalks", which gives their head a hammer-like look. The stalked eyes are usually sexually dimorphic, with eyestalks present but shorter in females.

The stalk-eyed flies are up to a centimeter long, and they feed on both decaying plants and animals. 

They are distributed throughout the Old world tropics, with the best-known species being from Southeast Asia and Southern Africa. Also, two species in North America have been described and a European species has recently been found in Hungary.

Stalk-eyed flies of the Diopsidae family have a distinct form of hypercephaly that has evolved under both natural and sexual selection. Female diopsids use male hypercephaly as an indicator of male quality.

Diplocaulus

Diplocaulus sculpture by Goro futura 

The Diplocaulus is known more by the name of hammerhead salamander rather than its original name on the internet. Unlike what they are mostly called, Diplocaulus wasn't actually a salamander, but is an extinct genus of lepospondyl amphibians that lived from the Late Carboniferous to the Late Permian of North America and Africa. Diplocaulus had a stocky, salamander-like body but was relatively large, reaching up to 1 m (3.3 ft) in length.

E.C. Olson proposed in 1951 that the horns could have supported skin flaps that could have assisted the animal in skate- or stingray-like locomotion. He did, however, admit that his suggestion was entirely speculative due to a lack of soft tissue evidence.

In a 1980 paper, South African paleontologist Arthur Cruickshank and fluid dynamicist B.W. Skews presented a new hypothesis for the function of the horns. They proposed that the tabular horns functioned as a hydrofoil, allowing the animal to better control the flow of water over its head.

During their research, Cruickshank and Skews built a full-scale model of a Diplocaulus' head and a portion of its body out of balsa wood and modeling clay. The model was put through several tests in a wind tunnel to determine drag, lift, and other forces experienced by the head in various situations.

The results showed that the horns generated significant lift, allowing the animal to rise quickly and easily in the water column of a river or stream.

Hammerhead worms

Hammerhead worm by Ben G. Thomas via YouTube

The Bipalium is a genus of large predatory land planarians. Because of the distinctive shape of their head region, they are sometimes referred to as "hammerhead worms" or "broadhead planarians." Hammerhead worms have been mistakenly called hammerhead slugs because they move in a slug-like fashion. They use cilia on their creeping sole to glide over a strip of mucus. The worms have also been observed lowering themselves down a string of mucus. 

Several species of bipalium are considered invasive in the United States, Canada, and Europe.

Bipalium species are predatory. Some species prey on earthworms, while others may also feed on mollusks.

In 2014, the presence of tetrodotoxin, a very dangerous neurotoxin, was recorded in B. adventitium and B. kewense. It was the first time tetrodotoxin had been found in terrestrial invertebrates.

Hammerkops

Hammerkops by Charles J. Sharp via Wikimedia commons 

The hammerkops, also known as the hammerhead stork, is the only species in the Scopus genus and family Scopidae. The shape of thier head, with a long bill and crest at the back, is reminiscent of a hammer, so the Afrikaans word for hammerhead was used to name this species. They are Africa's smallest stork.

These birds are well-known for their sturdy, three-tiered nests. The nest can be up to 180 cm (6 ft.) high, 180 cm (6 ft.) wide, and weigh between 24.75 and 49.5 kg (55 to 110 lbs.) and is constructed from sticks, reeds, grass, and dead plant stems arranged in a tree fork, on a cliff, or the ground. It takes 3 to 4 months to build such a structure, and they frequently serve as nesting sites for other species such as owls, geese, ducks, kestrels, and pigeons.

According to superstition, hammerkops are bad omens, and harming them is considered bad luck. These superstitions have kept the birds somewhat safe.

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References

• https://repository.naturalis.nl/pub/317859
• https://link.springer.com/article/10.1007/BF00605457
• https://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/diopsidae
• shorturl.at/cFIJQ
• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7088038/
• https://www.iucnredlist.org/species/22697356/93610351
• https://birdsoftheworld.org/bow/species/hamerk1/1.0/introduction
• https://royalsocietypublishing.org/doi/10.1098/rspb.1980.0110
• https://pubmed.ncbi.nlm.nih.gov/30060639
• https://www.jstor.org/stable/2423970?origin=crossref