Body-plan notes behind each stand-in sketch.
No photographic main references were used. Every plate was drawn from the textual body-plan notes and measurements in the sources below; nothing was traced from a specific published illustration.
Skull length 2–3 cm and presacral length about 10 cm from Kemp (2005), as quoted in the Wikipedia entry. Fur inferred from grooming glands, not skin. https://en.wikipedia.org/wiki/Morganucodon
A Grok and Midjourney approximation, not a peer-reviewed plate.Arboreal build from the Dormaal ankle bones; teeth and jaws only, no complete skeleton. Solé et al. (2014), via Sci.News and National Geographic coverage. https://www.sci.news/paleontology/science-dormaalocyon-latouri-mammal-origins-carnivoraforms-01671.html
A Grok and Midjourney approximation, not a peer-reviewed plate.Longer hindlimbs and counterbalancing tail from Rose (1982) and Thewissen & Hussain (1990). Mass for close species under 1 kg. https://pmc.ncbi.nlm.nih.gov/articles/PMC3482349/
A Grok and Midjourney approximation, not a peer-reviewed plate.Skull length about 6–7 cm from the measured SAM-PK specimens in the Sookias et al. cranial data. https://royalsocietypublishing.org/rsos/article-supplement/95853/pdf/rsos200116supp2/
A Grok and Midjourney approximation, not a peer-reviewed plate.Holotype about 26 cm as preserved; living length estimated near 30 cm. Zhu et al. (2009) and subsequent squamation work. https://en.wikipedia.org/wiki/Guiyu_oneiros
A Grok and Midjourney approximation, not a peer-reviewed plate.Shoulder height about 90 cm, long neck, slender limbs, no hump. Wikipedia summary and Hartman skeletal reconstruction (length ~1.7 m). https://en.wikipedia.org/wiki/Poebrotherium https://www.skeletaldrawing.com/synapsids/poebrotherium-wilsoni/
A Grok and Midjourney approximation, not a peer-reviewed plate.Cat-sized, about 3 kg, hindlimbs longer than forelimbs, no horns. Leptomerycidae accounts (Wikipedia / family summaries). Placement outside crown Pecora is noted as a caveat. https://en.wikipedia.org/wiki/Leptomerycidae
A Grok and Midjourney approximation, not a peer-reviewed plate.Late Ludlow Kuanti Formation, ~419 Ma; stem gnathostome with premaxilla, maxilla and dentary. Zhu et al. (2013), Nature. https://www.nature.com/articles/nature12617
A Grok and Midjourney approximation, not a peer-reviewed plate.Total length 20–25 cm including the tail; lizard-like. Wikipedia summary; already on the sauropsid side, and a 2025 analysis places it outside crown Amniota. https://en.wikipedia.org/wiki/Hylonomus
A Grok and Midjourney approximation, not a peer-reviewed plate.Smaller individuals about 10–23 kg; forefeet at least four digits, hindfeet five with one rudimentary. Wikipedia / Bajpai et al. descriptions. https://en.wikipedia.org/wiki/Cambaytherium
A Grok and Midjourney approximation, not a peer-reviewed plate.KNM-BG 35250: proportionally large forelimbs and long pedal digits; lacks the suspensory specializations of living apes. Ishida et al. (2004) skeleton description. https://www.sciencedirect.com/science/article/abs/pii/S0047248403001489
A Grok and Midjourney approximation, not a peer-reviewed plate.Cranial length comparable to a gray fox, fisher, or raccoon; mesocarnivore, scansorial. Tomiya (2011), PLOS One. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0024146
A Grok and Midjourney approximation, not a peer-reviewed plate.Known from nearly complete Early Cretaceous crania; used as a near-therian body-plan stand-in. Rougier, Wible & Hopson (1992), JVP. https://www.tandfonline.com/doi/abs/10.1080/02724634.1992.10011449
A Grok and Midjourney approximation, not a peer-reviewed plate.Already on the whale stem; aquatic wader with dense limb bones, but still terrestrial in build. Thewissen et al. (2007), Nature. https://www.nature.com/articles/nature06343
A Grok and Midjourney approximation, not a peer-reviewed plate.Small early Miocene bovid with short horn cores; one of the oldest known bovids. Wikipedia summary of the genus. https://en.wikipedia.org/wiki/Eotragus
A Grok and Midjourney approximation, not a peer-reviewed plate.Skull about 31 mm; body mass estimated near 49 g. Macrini et al. cranial endocast paper. https://www.researchgate.net/publication/229423807_Digital_cranial_endocast_of_Pucadelphys_andinus_a_Paleocene_metatherian
A Grok and Midjourney approximation, not a peer-reviewed plate.Body mass estimates cluster near 48 g, in the range of the smaller mouse lemurs. Source: ScienceDirect.
A Grok and Midjourney approximation, not a peer-reviewed plate.About 2 kg, fox-like, oldest known canine; designed for snatching small prey. Source: Wikipedia.
A Grok and Midjourney approximation, not a peer-reviewed plate.Mean body-size estimate about 394 g, near a male teal or female grey partridge; near the Galloanserae node. Source: Nature.
A Grok and Midjourney approximation, not a peer-reviewed plate.Skull about 9 cm; most likely body-mass estimate about 3.5 kg. Source: Wikipedia.
A Grok and Midjourney approximation, not a peer-reviewed plate.Early Miocene deer with simple dichotomous antlers. https://link.springer.com/article/10.1007/s00114-020-01713-x
A Grok and Midjourney approximation, not a peer-reviewed plate.One of the earliest North American rodents; squirrel-like body plan. https://royalsocietypublishing.org/rspb/article/283/1823/20152316/84349/Virtual-endocasts-of-Eocene-Paramys-Paramyinae
A Grok and Midjourney approximation, not a peer-reviewed plate.Early pantherine; closest living morphological comparison is the snow leopard, but it is not that species. https://www.si.edu/newsdesk/photos/life-reconstruction-p-blytheae
A Grok and Midjourney approximation, not a peer-reviewed plate.No fossil is confidently placed at the Boreoeutheria node, so this is a generic small early placental body plan (shrew-like, long tail), not a reconstruction of any species.
A Grok and Midjourney approximation, not a peer-reviewed plate.Card illustration after Hunt (2001).
A Grok and Midjourney approximation, not a peer-reviewed plate. Hunt (2001).