The transitional cheek bones of Ochotona, the pika
I misunderstood this earlier,
likely because it is a trait not found in any other tested taxon. This trait is not scored in the LRT. Hope you find this as interesting as I did.
Figure 2. Pika is a basal rabbit that prefers mountainous terrain. A sister, Henkelotherium, goes back to the Late Jurassic.
” data-medium-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2018/12/pika_invivo224.jpg?w=224″ data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2018/12/pika_invivo224.jpg?w=224″ class=”size-full wp-image-34601″ src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2018/12/pika_invivo224.jpg” alt=”Figure 2. Pika is a basal rabbit that prefers mountainous terrain. A sister, Henkelotherium, goes back to the Late Jurassic.” width=”224″ height=”253″ srcset=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2018/12/pika_invivo224.jpg 224w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2018/12/pika_invivo224.jpg?w=133&h=150 133w” sizes=”(max-width: 224px) 100vw, 224px” />
Figure 2. Pika is a basal rabbit that prefers mountainous terrain. A sister, Henkelotherium, goes back to the Late Jurassic.
This is Ochotona, the extant pika,
(Figs 1, 2) transitional from rats to rabbits, chinchillas, guinea pigs and jerboas in the large reptile tree (LRT, 2337 taxa). Note the double joining of the squamosal with the cranium in dorsal view. This appears to be a transitional anatomy as the otic capsule expands. Also note the lack of a jaw joint in the mandible = dentary.
Instead the dentary is carried
and moved in a sling of jaw muscles making it highly mobile for grinding herbivorous foods.
This is the opposite of
carnivore jaw joints, which articulate in a cylindrical jaw joint enabling open-close motion and precise alignment of the cutting teeth.
Figure 1. Ochotona skeleton and skull. Note the double joining of the squamosal with the cranium in dorsal view. This appears to be a transitional anatomy as the otic bulla expands. Also note the lack of a jaw joint in the mandible = dentary.
” data-medium-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/02/ochotona_skull3views588.jpg?w=297″ data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/02/ochotona_skull3views588.jpg?w=584″ class=”size-full wp-image-91768″ src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/02/ochotona_skull3views588.jpg” alt=”Figure 1. Ochotona skeleton and skull. Note the double joining of the squamosal with the cranium in dorsal view. This appears to be a transitional anatomy as the otic bulla expands. Also note the lack of a jaw joint in the mandible = dentary.” width=”584″ height=”589″ srcset=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/02/ochotona_skull3views588.jpg?w=584&h=589 584w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/02/ochotona_skull3views588.jpg?w=150&h=150 150w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/02/ochotona_skull3views588.jpg?w=297&h=300 297w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/02/ochotona_skull3views588.jpg 588w” sizes=”(max-width: 584px) 100vw, 584px” />
Figure 1. Ochotona skeleton and skull. Note the double joining of the squamosal with the cranium in dorsal view. This appears to be a transitional anatomy as the otic bulla expands. Also note the lack of a jaw joint in the mandible = dentary.
In taxa preceding Ochotona
the squamosal does not have a double articulation with the cranium butthe dentary is still carried in a muscular sling in front of the squamosal articulation. In taxa following Ochotona, like Chinchilla (Fig 2), a single squamosal articulation is present at the site of the anterior of the two found in Ochotona. The former posterior cranial connection is dissolved. Perhaps this evolved as the otic capsule = bulla further expanded (Fig 2).
Hearing became more acute in rabbits, chinchillas and jerboas.
Figure 3. The skull and skeleton of Chinchilla, the chinchilla. Note the huge otic capsula= bulla (yellow).
” data-medium-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/02/chinchilla_588.jpg?w=236″ data-large-file=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/02/chinchilla_588.jpg?w=584″ class=”wp-image-91772 size-full” src=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/02/chinchilla_588.jpg” alt=”Figure 3. The skull and skeleton of Chinchilla, the chinchilla. Note the huge otic capsula= bulla (yellow). Here the squamosal articulation forms a postorbital bar.” width=”584″ height=”744″ srcset=”https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/02/chinchilla_588.jpg?w=584&h=744 584w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/02/chinchilla_588.jpg?w=118&h=150 118w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/02/chinchilla_588.jpg?w=236&h=300 236w, https://pterosaurheresies.wordpress.com/wp-content/uploads/2025/02/chinchilla_588.jpg 588w” sizes=”(max-width: 584px) 100vw, 584px” />
Figure 3. The skull and skeleton of Chinchilla, the chinchilla. Note the huge otic capsula= bulla (yellow). Here the squamosal articulation forms a postorbital bar.
Ochotona princeps
(originally Lepus dauuricus Pallas, 1776; Link 1795; Richardson 1828) is the extant pika, a rock-dwelling herbivore nesting basal to rabbits. Pikas live in mountainous areas in Asia and North America. Fossil pikas are known from the Miocene, 16mya, to the recent.
References
Link HF 1795. Über die Lebenskräfte in naturhistorischer Rücksicht und die Classification der Säugthiere. – Beyträge zur Naturgeschichte (Rostock, Leipzig) 2: 1-41.
Source: https://pterosaurheresies.wordpress.com/2025/02/18/the-transitional-cheek-bones-of-ochotona-the-pika/
Anyone can join.
Anyone can contribute.
Anyone can become informed about their world.
"United We Stand" Click Here To Create Your Personal Citizen Journalist Account Today, Be Sure To Invite Your Friends.
Before It’s News® is a community of individuals who report on what’s going on around them, from all around the world. Anyone can join. Anyone can contribute. Anyone can become informed about their world. "United We Stand" Click Here To Create Your Personal Citizen Journalist Account Today, Be Sure To Invite Your Friends.
LION'S MANE PRODUCT
Try Our Lion’s Mane WHOLE MIND Nootropic Blend 60 Capsules
Mushrooms are having a moment. One fabulous fungus in particular, lion’s mane, may help improve memory, depression and anxiety symptoms. They are also an excellent source of nutrients that show promise as a therapy for dementia, and other neurodegenerative diseases. If you’re living with anxiety or depression, you may be curious about all the therapy options out there — including the natural ones.Our Lion’s Mane WHOLE MIND Nootropic Blend has been formulated to utilize the potency of Lion’s mane but also include the benefits of four other Highly Beneficial Mushrooms. Synergistically, they work together to Build your health through improving cognitive function and immunity regardless of your age. Our Nootropic not only improves your Cognitive Function and Activates your Immune System, but it benefits growth of Essential Gut Flora, further enhancing your Vitality.
Our Formula includes: Lion’s Mane Mushrooms which Increase Brain Power through nerve growth, lessen anxiety, reduce depression, and improve concentration. Its an excellent adaptogen, promotes sleep and improves immunity. Shiitake Mushrooms which Fight cancer cells and infectious disease, boost the immune system, promotes brain function, and serves as a source of B vitamins. Maitake Mushrooms which regulate blood sugar levels of diabetics, reduce hypertension and boosts the immune system. Reishi Mushrooms which Fight inflammation, liver disease, fatigue, tumor growth and cancer. They Improve skin disorders and soothes digestive problems, stomach ulcers and leaky gut syndrome. Chaga Mushrooms which have anti-aging effects, boost immune function, improve stamina and athletic performance, even act as a natural aphrodisiac, fighting diabetes and improving liver function. Try Our Lion’s Mane WHOLE MIND Nootropic Blend 60 Capsules Today. Be 100% Satisfied or Receive a Full Money Back Guarantee. Order Yours Today by Following This Link.
| Online: | |
| Visits: | 1,676,298,028 |
| Stories: | 8,350,334 |
Whistler Blowers, Insiders
