The morphological mix barely evolves: thin disks survive predicted merger schedules, settled disks fill the sky by z of 1 to 2, and JWST finds barred spirals at z near 3 indistinguishable from local analogs with type ratios approximately constant to z near 10 (Ferreira 2024; Avila-Reese 2007). The model predicts churn; the universe shows preservation.
Hierarchical assembly makes morphology an ongoing negotiation: mergers build spheroids, accretion rebuilds disks, and the mix must track the merger rate, growing more disturbed toward early times. A constant mix and fragile disks surviving their own merger schedule require fine-tuned suppression the framework does not supply.
SCT reads the stall as exactly what it looks like: preservation of an initial condition. Morphological type is set at the seeding epoch by the angular momentum the formation deposit carried, the J/J_circ ratio selecting spiral, spheroidal, or irregular structure (P31), and is thereafter protected by the one conservation law thermalization itself cannot erase: Noether's theorem guarantees angular momentum is redistributed, never destroyed (P32, P30). A galaxy's structural type is its J inheritance wearing stars, so the type ratio is fixed by the cascade's impact-parameter distribution (P34) at deposition and carried forward essentially unchanged, which is precisely the observed constancy to z near 10.
The model's two embarrassments resolve together: thin disks survive because their high-J inheritance is conserved through perturbations that merely redistribute it, and simulations overproduce bulges because they manufacture morphology through mergers that SCT never needed. The registered forward test is the early-disk census: SCT requires the disk fraction to exceed 10 percent even at z above 10, where merger-driven assembly predicts disturbance dominating. The seeding-epoch morphology mechanics are in Paper 4, From Chaos To Collisothermal Cosmogenesis, Section 3.3, the same principle carrying bulge-disk decoupling (recid 114), the ring galaxies (recid 104), and the merger-rate sector (recid 110).
Keystone economy: P31 sets the type, P32 keeps it. The stall is not a failure of evolution; it is conservation law doing its job.
The registered kill: a definitive JWST morphological census of confirmed z > 10 galaxies finding the disk fraction consistently below 5 percent, comparable to the merger-dominated expectation, would refute the seeded-morphology reading. At the population level, Euclid's billion-galaxy catalog finding type fractions that track merger-history indicators rather than holding constant, with thin-disk survival correlated to quiet merger luck, would restore the hierarchical negotiation and remove the M3 mechanism.