#chordata

[snototter]

A group of long billed corellas (Cacatua tenuirostris) take flight in Robe, South Australia

by Ian Colley

[alfafilly]

Hair Studies

Hair studies I did as apart of my friend Rodentblood's Art School that he does on stream! I've wanted to study hair for awhile and up my game on it... I gotta keep trying, but this was fun! Messed with a painty style as well, as I miss doing it. It's been years!

Posted using PostyBirb

[wikipediapictures]

Rufous fieldwren

“Rufous Grasswren, Broken Hill, New South Wales, Australia.” - via Wikimedia Commons

[strawlessandbraless]

Skeleton Panda Sea Tunicate Appreciation Post!!! 💀 🐼 🌊

Clavelina ossipandae, the skeleton panda sea tunicate is a species of colonial ascidian, also known as sea tunicates, a group of sessile, marine filter-feeding invertebrates. Just some funky little guys!

First discovered near Kume Island in Japan by local divers, pictures of the animal attracted media attention in 2017. But they weren't given their formal taxonomic description until 2024

Love to sea it 🌊

[reanimateobjects]

[acarinarium]

Do you ever just think about sturddlefish? I do

[chordata-art]

hagfish :3

[faunalregion]

[bestanimal]

Round 2 - Chordata - Chondrichthyes

(Sources - 1, 2, 3, 4)

Chondrichthyes is a class of jawed fish, commonly called “cartilaginous fish” due to their skeletons composed mainly of cartilage, making them distinct from all other vertebrates. They are comprised of the superorders Selachimorpha (“Sharks”), Batoidea (“Rays”), and Holocephalimorpha (“Chimaeras”).

Chondrichthyans breath through gills but lack opercula (gill coverings) and swim bladders. They have paired fins, paired nares (nostrils), and placoid (tooth-shaped) scales (except for electric rays, which have loose, soft skin). These placoid scales, also called dermal denticles, provide protection and streamlining, giving the animal’s skin a sandpaper-y feel. All chondrichthyans breathe through five to seven pairs of gills, depending on the species. As a general rule, pelagic species usually must keep swimming to keep oxygenated water moving through their gills, while demersal species can actively pump water in through their spiracles (a small hole or slit behind each eye) and out through their gills. Most larger, pelagic species no longer have spiracles. Chondrichthyans have many sensory organs to perceive the world around them. Their nostrils are attached to powerful olfactory organs. Around their face are a network of electroreceptors called Ampullae of Lorenzini, which allow them to sense electrical fields. Their lateral line has modified epithelial cells which sense motion, vibration, and pressure in the water around them. However, their sound-detecting apparatus has limited range and is typically more powerful at lower frequencies. Some species have electricity-producing organs which can be used for defense and predation. Chondrichthyans have a diverse array of shapes and sizes, ranging from the 10 cm (3.9 in) long, electric Finless Sleeper Ray (Temera hardwickii) to the over 10 m (33 ft) long Whale Shark (Rhincodon typus). All species are carnivores: some predatory, some ambush-hunters, and some filter-feeders. At least one species is omnivorous. Chondrichthyans have internal fertilization and most species give live birth, while some lay eggs. There is no parental care after birth, though some chondrichthyans do guard their eggs.

Chondrichthyans are considered to have evolved from Acanthodians, which appear from the Early Silurian. The first sharks began to evolve in the Devonian Period, though, while often claimed to be relatively unchanged, modern forms did not start appearing until the Early Jurassic.

Propaganda under the cut:

Mentioned briefly above, the Bonnethead Shark (Sphyrna tiburo), a small species of hammerhead, is the only shark known to be omnivorous. While it feeds on crustaceans, molluscs, and small fish, it also ingests large amounts of seagrass, which has been found to make up around 62% of gut content mass.

Also mentioned briefly above, Electric Rays (order Torpediniformes) are known for being capable of producing an electric discharge, ranging from 8 to 220 volts, depending on species, used to stun prey and for defense.

There are over 500 different species of sharks, and only a dozen could be considered dangerous to humans. That being said, of those 12, most do not seem to like the taste of human flesh, and bites are usually accidental or exploratory.

Many pelagic chondrichthyans occasionally breach, leaping out of the water. This can be done for hunting purposes, as a mating ritual, to shake off parasites, or even just for fun!

Today, all species of Sawfish (family Pristidae) are critically endangered. However, they were relatively common in the Cretaceous, where they were likely a common food source for Spinosaurus.

(Confusingly, Sawfish are a type of ray while Sawsharks (order Pristiophoriformes) are a type of shark. Sawsharks live in the deep sea and are rarely seen, while sawfish live in coastal and brackish waters.)

Kitefin Sharks (family Dalatiidae) have bioluminescent organs which glow blue in the dark

Chimaeras have a strange pair of teeth in their lower jaw which look like rodent incisors, giving them the common names “ratfish” or “rabbitfish.”

Great White Sharks (Carcharodon carcharias) are regularly hunted by orcas, and when one is confronted by an orca it will generally flee and not return to that area for up to a year.

Manta Rays (genus Mobula) are incredibly smart. They were the first “fish” in the world to pass the “mirror test” (ie show self-awareness by recognizing themselves in a mirror rather than seeing the reflected image as another manta ray). They also have highly-developed long-term memory, form friendships, and play with each other by blowing bubbles and breaching out of the water.

[ppaleoartistgallery]

#Paleostream 19/04/2025

here's today's #Paleostream sketches!!!

today we sketched Tullimonstrum (Tully Monster), Ornithosuchus, Xerces blue, and Ninjemys

[snototter]

A great blue heron (Ardea herodias) takes flight in a field of marsh knotweed at Lake Cuyamaca, California, USA

by Robyn Waayers

[twilightofthesandwiches]

[wikipediapictures]

Tompot blenny

“Parablennius gattorugine” - via Wikimedia Commons

[lemonlemonfry]

[reanimateobjects]